A class of scaling functions projective synchronization between uncertain laser spatiotemporal networks with different number of nodes is researched. Through designing appropriate controllers, not only the projective synchronization between discrete uncertain spatiotemporal networks with different number of nodes is realized, but also the coupling matrix element representing the topological structure of the network, the feedback strength and scale function are determined at the same time. By taking the spatiotemporal network composed of one-dimensional ring cavity laser model and electro-optical bidirectional coupled lattice model as an example to simulate, the number of network nodes is arbitrarily set according to actual needs, and it is found that the synchronization performance of the uncertain spatiotemporal network is very stable, which shows that this method is feasible.