With the growing demand for massive file storage and high number of concurrent accesses to enhance performance of the system. In this paper, we propose an optimization strategy of web applications, which can expand the storage capacity, availability and reliability with MongoDB GridFS, and also can support load balancing and hot standby with Nginx and Keepalived, optimizing concurrent performance. We test the concurrent performances of the web application and the experimental results show that the average response time could be reduce by 9% when the number of concurrent accesses increases to more than 80. When files are uploaded concurrently through Nginx Gridfs, the performance is stable.The file-download speeds of larger files are faster than those through local file system EXT4.