The invention relates to an asymmetric restart method for an STATCOM power module and a control system. The return state of each power module is detected, and in the case of an anomaly, the STATCOM stops working; when the STATCOM meets a redundancy operation condition, an abnormal power module bypass is controlled; the triangular carrier frequency of each normal power module of each phase, the initial phase delay of modulated triangular waves and a DC voltage given value are re-adjusted; parameters after being adjusted are allocated to each corresponding power module; and the abnormal state of the abnormal power module is shielded, each normal power module is re-controlled, and asymmetric restart is realized. Through bypass positioning operation on the abnormal power module, the control parameters are re-adjusted, asymmetric restart control is finally controlled, maximum restart for the STATCOM after failure is realized, and the problems of reliability and applicability existing in the existing chain STATCOM power module bypass mode and the restart method can be solved.