The system defines and limits the choices of people. Under the conditions of joint action and single action, investors' rights and interests are difficult to be fully compensated according to the existing legal framework and operating mechanism. In the case of securities support litigation, the burden of lawyer fee is transferred to the China Securities Investor Services Center, so the litigation costs of the investors are reduced, and the size of the group can expand due to the permission of free-rider. In view of the trade-off between public law enforcement costs and private law enforcement costs, securities support litigation is an organic combination of public law enforcement and private law enforcement, which helps to improve law enforcement efficiency and reduce social costs. Under existing conditions, securities support litigation, joint action and individual action will exist in parallel. From the perspective of protecting investor rights and improving judicial efficiency, we propose to allow the lawyer's risk agency system to transfer from "opting" to "opting out" and reveal evidence fully before the court hear the case.