首先给出SM2p256v1椭圆曲线的建议参数如下：

default_ecc_table = {
    'n': 'FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123',
    'p': 'FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF',
    'g': '32c4ae2c1f1981195f9904466a39c9948fe30bbff2660be1715a4589334c74c7'
         'bc3736a2f4f6779c59bdcee36b692153d0a9877cc62a474002df32e52139f0a0',
    'a': 'FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC',
    'b': '28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93',
}

椭圆曲线点加（x1，y1）+（x2，y2）

tSm2 = sm2.CryptSM2('', '')
xy_h = tSm2._convert_jacb_to_nor(tSm2._add_point(x1_h+y1_h, x2_h+y2_h))
x_h = xy_h[0:64]
y_h = xy_h[64:]

椭圆曲线点减（x1，y1）-（x2，y2）

p = int.from_bytes(bytes.fromhex(sm2.default_ecc_table['p']))
_y2 = p - y2
tSm2 = sm2.CryptSM2('', '')
_y2_h = hex(_y2).replace('0x','')
xy_h = tSm2._convert_jacb_to_nor(tSm2._add_point(x1_h + y1_h, x2_h + _y2_h))
x_h = xy_h[0:64]
y_h = xy_h[64:]

椭圆曲线倍点k*（x1，y1）

tSm2 = sm2.CryptSM2('', '')
xy_h = tSm2._kg(int(k_h, 16), x1_h + y1_h )
x_h = xy_h[0:64]
y_h = xy_h[64:]

实现结果：