SVPWM can improve the using efficiency of dc voltage much, and its control principle is so simple that it can be easily realized on microcomputer. If it is introduced into the VSC-HVDC which powers to passive network, it will have good performance. This paper firstly introduces the principle of VSC HVDC and the SVPWM technology, then discusses how to realize the SVPWM technology on microcomputer and establish the SVPWM physical model in PSCAD/EMTDC availably. Furthermore, VSC HVDC physical model is established in PSCAD/EMTDC and validated, the results show that this method which applys the SVPWM on passive network is feasible.