This paper investigates the photon antifocusing effect in a four-wave mixing coupled system embedded with a two-level atom. Through analytical analysis of the system, we obtain the optimal conditions for achieving photon blockade. Subsequently, numerical results are obtained by solving the main equation in the steady-state limit. Our findings reveal that the analytical optimal conditions are consistent with the numerical results, demonstrating that this system can realize nontraditional photon blockade. Further, a detailed discussion is presented on the influence of various system parameters on achieving nontraditional photon blockade. The results indicate that the four-wave mixing coupling interaction and atom-cavity coupling coefficient significantly enhance the nontraditional photon blockade effect.