The receiving end of the hybrid cascaded DC transmission system adopts a series structure composed of a line commutated converter (LCC) and parallel-connected modular multilevel converter (MMC) modules. This special structure has been applied in practical engineering. However, due to the extremely unavoidable first phase change failure of LCCs and the complex electrical characteristic relationship between LCCs and MMCs at the receiving end, the control strategy for suppressing the subsequent phase change failure at the receiving end of the hybrid cascaded DC transmission system has become difficult. To this end, a joint control strategy for suppressing subsequent phase change failure in hybrid cascaded DC transmission systems is proposed, which is to convert the variation of the inverter-side LCC extinction angle into the reactive power issued by the MMC, and to carry out a reasonable reactive power allocation of the MMC, and at the same time, to add a nonlinear voltage dependent current order limiter (VDCOL) control strategy in the LCC to achieve effective suppression of subsequent phase change failures in the hybrid cascaded DC transmission system. A simulation model is constructed in PSCAD to analyze the proposed joint control strategy, and the correctness of the proposed method and its adaptability to multiple faults are verified.