The invention discloses a working platform task allocation method and system based on multiple roles, and relates to the technical field of computer application. The system comprises a working platform, a client terminal and a user terminal, wherein the working platform is in bidirectional connection with the client terminal and the user terminal through a wireless communication network; the working platform comprises an authority management module, a task matching module, a task tracking module, a risk assessment module, a task storage module and a cost calculation module; the client terminalcomprises a task publishing module, an allocation mode selection module, an information viewing module and a payment module; the user terminal comprises a role input module, a label configuration module and an overdue reminding module. A task request is issued through a client terminal, a working platform performs risk level evaluation, a multi-role task allocation mechanism is expanded, and tasks and multiple roles are quickly matched; and multiple distribution mechanisms are adopted, so that the diversity of task distribution is ensured, multi-role cooperative efficient work is realized, and the task distribution efficiency is improved.