Users location sharing in social network has become a hot issue nowadays. Traditional privacy preserving schemes are easily attacked by Hacker, which can result in leaking of sensitive information. And in the case of fewer users or shorter stay time, the information sharing efficiency is low and the privacy protection effect is not obvious. Some researchers proposed MobiShare scheme to solve this disadvantage, nevertheless, the cost of cellular tower in MobiShare system is too high lacking of practicability. MobiShare is a location-based service that assists users with searching and sharing files. To address the above problems, this paper proposes an improved privacy preserving scheme by improving MobiShare for the users location sharing in social network. Firstly, we optimize the traditional structure of MobiShare. Additionally, asymmetric encryption and Bloom filter are combined to enhance the security and efficiency of new scheme. Finally, performance and security analysis are proved to illustrate the availability of our new scheme. Experimental results show that our improved MobiShare scheme displays a better effectiveness for privacy preserving scheme.