By introducing concept of gravitational field, synchronization issue of chaotic system is equivalent to orbit consistency of the system in the gravitational field. By this approach the realization of synchronization can be obtained in those chaotic systems with different dynamics. Since the coupling between different chaotic systems is defined as velocity variable which has nothing to do with equation of motion and is different from regular synchronization controller, the proposed method is a more general one for chaos synchronization. Based on orbit approximation, the conditions for synchronization of multiple chaotic systems in gravitational field are derived, and synchronous orbit equation is given. Numerical simulations show the effectiveness of the proposed method.