N Fitzhugh-Nagumo models are used as network nodes, and synchronization of spatiotemporal chaos is studied using a all-to-all network constructed through a nonlinear coupling. The general principle of selecting coupling functions between nodes of the complex network is introduced. The theoretical analysis of the conditions for synchronization is made and the range of the feedback gain is obtained based on Lyapunov stability theory. The simulation is made to test the synchronization effect of the spatiotemporal chaos of the all-to-all network whose nodes are Fitzhugh-Nagumo models. The results show that the synchronization is fast and efficient, and the size of the network size has no sensitive effect on the stability of the network synchronization.