This paper aims to address cooperative tracking control problem of cross-domain heterogeneous unmanned systems via adaptive neural backstepping approach. Firstly, based on unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned surface vehicles (USVs), the mathematical modeling of the cross-domain heterogeneous unmanned systems is carried out. Then, to construct the communication network of the cross-domain heterogeneous unmanned systems, the network topology theory is employed. Moreover, combined with distributed backstepping approach and radial basis function neural network, the adaptive controller is designed to realize the distributed cooperative tracking control of cross-domain heterogeneous unmanned systems. Furthermore, the three-dimensional motion environment modeling of the cross-domain heterogeneous unmanned systems is developed through MATLAB-NETLOGO co-simulation platform. Based on this, the visualization display of cooperative tracking control of cross-domain heterogeneous unmanned systems is achieved. Finally, by example analysis, the proposed distributed cooperative tracking algorithm for cross-domain heterogeneous unmanned systems is reliable and effective.