Model checking is an automatic verification approach based on the state-space exploration strategy, which can effectively improve the quality of a program. However, due to the non-deterministic of thread scheduling and the complexity of data synchronization, the state-space explosion problem in concurrent program verification is more serious. At present, the independence analysis based partial-order reduction techniques have been widely applied to reduce the exploration space of concurrent program verification tasks. In the face of the problem that imprecise independence analysis will significantly increase the number of equivalent trace classes to be explored, a concurrent program model checking tool CDG4CPV that can refine the dependencies between thread transitions has been developed. Firstly, specification automata are constructed corresponding to the reachability property. Then, a constrained dependency graph is constructed according to the types of transition edges of threads and the access information of shared variables. Finally, the constrained dependency graph is utilized to prune the independent and enabled branches when unwinding the control-flow graph. The experiments have been carried out on the concurrency track of SV-COMP 2022 benchmark suite, and the efficiency of the proposed tool is also compared and analyzed. Empirical results show that the proposed tool can effectively improve the efficiency of model checking for concurrent programs. Specially, compared with the BDD-based program analysis algorithm, the proposed tool reduces the number of explored states by 91.38%, and the time and memory overheads are reduced by 86.25% and 69.80%, respectively.