The existing researches on crowdsourcing task assignment don′t involve in measuring the uncertainty of workers′ qualification, and don′t achieve the collaborative assignment in many-to-many mode between tasks and workers from the angle of crowdsourcing platform. Thus, an assignment approach of software crowdsourcing tasks was proposed supporting the fuzzy measurement of workers qualification and role collaboration. Integrating the past performance of workers and the expectation of tasks′ demands, this approach employed fuzzy interval numbers to evaluate the multiple attributes ability matching degree, and aggregated the comprehensive qualification via the fuzzy analytic hierarchy process method. By introducing the role-based collaboration theory, the many-to-many software crowdsourcing tasks assignment was formulated as a combinatorial optimization problem related to a task set and a worker group, and the constraints, including the tasks′ weights, quantity of workers and potential conflicts, were used to enhance the efficiency and success rate of tasks assignment. A solution based on the CPLEX package was presented to solve the problem. Simulation experiments show that this method can efficiently and accurately realize the collaborative allocation of crowdsourcing tasks under the premise of ensuring the best completion quality of global tasks.