由于不同版本的pcl兼容范围不一样，这里有2个版本的代码，里面的文件路径需要实际情况修改即可，希望对您有所参考或帮助

pcl1.8.1和vs2015版本代码

#include <iostream>
#include <pcl/io/io.h>
#include <pcl/io/pcd_io.h>
#include <pcl/io/vtk_lib_io.h>
#include <pcl/point_cloud.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <boost/thread/thread.hpp>

using namespace std;
using namespace pcl;

int main() {
    // 读取STL格式模型
    vtkSmartPointer<vtkSTLReader> reader = vtkSmartPointer<vtkSTLReader>::New();
    reader->SetFileName("Spider_ascii.stl");
    reader->Update();
    vtkSmartPointer<vtkPolyData> polydata = reader->GetOutput();

    if (!polydata) {
        std::cerr << "Failed to load STL file." << std::endl;
        return -1;
    }

    pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>());
    pcl::io::vtkPolyDataToPointCloud(polydata, *cloud);

    // 创建PCLVisualizer显示STL文件
    boost::shared_ptr<pcl::visualization::PCLVisualizer> stl_viewer(new pcl::visualization::PCLVisualizer("STL Viewer"));
    stl_viewer->addModelFromPolyData(polydata, "mesh");

    // 创建新的线程显示STL窗口
    boost::thread stl_thread([&stl_viewer]() {
        while (!stl_viewer->wasStopped()) {
            stl_viewer->spinOnce(100);
            boost::this_thread::sleep(boost::posix_time::microseconds(100000));
        }
    });

    // 保存PCD文件
    pcl::io::savePCDFileASCII("Spider_ascii.stl.pcd", *cloud);

    // 加载点云文件
    pcl::io::loadPCDFile("Spider_ascii.stl.pcd", *cloud);
    std::cout << "Loaded PCD with " << cloud->points.size() << " points." << std::endl;

    // 创建PCLVisualizer显示PCD文件
    boost::shared_ptr<pcl::visualization::PCLVisualizer> pcd_viewer(new pcl::visualization::PCLVisualizer("PCD Viewer"));
    pcd_viewer->addPointCloud(cloud, "cloud");

    // 主要线程处理PCD显示
    while (!pcd_viewer->wasStopped()) {
        pcd_viewer->spinOnce(100);
        boost::this_thread::sleep(boost::posix_time::microseconds(100000));
    }

    // 等待STL显示线程结束
    stl_thread.join();

    return 0;
}

 以下代码适合pcl1.13.1 vs2022

#include <iostream>
#include <pcl/io/pcd_io.h>
#include <pcl/io/vtk_lib_io.h>
#include <pcl/point_cloud.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <boost/thread/thread.hpp>
#include <vtkSmartPointer.h>
#include <vtkSTLReader.h>
#include <vtkPolyData.h>

using namespace std;
using namespace pcl;

int main() {
    // 读取STL格式模型
    vtkSmartPointer<vtkSTLReader> reader = vtkSmartPointer<vtkSTLReader>::New();
    reader->SetFileName("Wuson.stl");
    reader->Update();
    vtkSmartPointer<vtkPolyData> polydata = reader->GetOutput();

    if (!polydata) {
        std::cerr << "Failed to load STL file." << std::endl;
        return -1;
    }

    pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>());
    pcl::io::vtkPolyDataToPointCloud(polydata, *cloud);

    // 创建PCLVisualizer显示STL文件
    boost::shared_ptr<pcl::visualization::PCLVisualizer> stl_viewer(new pcl::visualization::PCLVisualizer("STL Viewer"));
    stl_viewer->addModelFromPolyData(polydata, "mesh");

    // 创建新的线程显示STL窗口
    boost::thread stl_thread([&stl_viewer]() {
        while (!stl_viewer->wasStopped()) {
            stl_viewer->spinOnce(100);
            boost::this_thread::sleep(boost::posix_time::microseconds(100000));
        }
        });

    // 保存PCD文件
    pcl::io::savePCDFileASCII("Wuson.stl.pcd", *cloud);

    // 加载点云文件
    pcl::io::loadPCDFile("Wuson.stl.pcd", *cloud);
    std::cout << "Loaded PCD with " << cloud->points.size() << " points." << std::endl;

    // 创建PCLVisualizer显示PCD文件
    boost::shared_ptr<pcl::visualization::PCLVisualizer> pcd_viewer(new pcl::visualization::PCLVisualizer("PCD Viewer"));
    pcd_viewer->addPointCloud(cloud, "cloud");

    // 主要线程处理PCD显示
    while (!pcd_viewer->wasStopped()) {
        pcd_viewer->spinOnce(100);
        boost::this_thread::sleep(boost::posix_time::microseconds(100000));
    }

    // 等待STL显示线程结束
    stl_thread.join();

    return 0;
}