The VSM (Virtual Share Memory) middleware，which is design for satisfying the demand of transparent real-time data interactive in aerospace distributed simulation test system，improve the Real-time performance in distributed simulation system. But the stability of VSM in high payload is not satisfactory. Aiming to the demand of high stability in high payload of distributed simulation using VSM middleware, the scheme of VSM middleware base on publish/Subscribe is proposed. Through optimized the network transmission, the stability and real-time performance is improved by the VSM base on publish/subscribe in high payload.