国际私法中的“有利原则”是指适用有利于弱者的法律,但其作为一种法律选择原则和价值追求,还面临着如何在司法中具体贯彻和运用的问题。本文认为,这个合适的方法就是单方意思自治。单方意思自治既体现了保护弱方利益,促进了实质正义,又简化了司法任务,提高了效率。从而实现法律正义和效益的统一。 The “favorable principle” in private international law refers to the law applicable to the weak, but as a principle of legal choice and value pursuit, it also faces the problem of how to implement and apply it in the judicial system. This article argues that this suitable method is unilateral autonomy. The unilateral autonomy of purpose embodies the protection of the interests of the weaker, the promotion of substantive justice, the simplification of judicial tasks and the enhancement of efficiency. Thus realizing the unification of legal justice and benefit.