In the third part, the feynman rules of scalar qed is derived clearly, followed by photon self-energy and scalar self-energy . based on them, the effective masses of photon and scalar electron are given 在第三部分推导了标量qed的费曼规则,并计算了光子自能和标量自能,在此基础上得到光子和标量电子的有效质量。