To overcome deficiencies in the mobile tourism applications such as underutilization of mobile device capabilities and poor user experience, a low-cost and cross-platform mobile travel reservation system was designed. Based on business process optimization of client-side, the mobile app was built by using HTML5, CSS3 and jQuery technology. Additionally, the system uses Ajax asynchronous interactive technology to improve response time. The practical application of this system shows that it can work equally well on multiple mobile platform. The characteristics of flat UI design, convenient operation and good user experience stretch its application prospects.