1. A method for predicting a collision probability of space objects, comprising: allocating a plurality of space objects according to a total number of the plurality of space objects for parallel computation in a graphics processing unit (GPU) device; generating initial orbit states of the plurality of space objects by an initial-orbit-state generation kernel of the GPU device; performing an orbit propagation for each space object based on the initial orbit state to predict a state of each space object by an orbit propagation kernel of the GPU device; collecting the predicted states of the plurality of space objects by a predicted-orbit-state collection kernel of the GPU device; performing a real-time visualization and rendering of the predicted space objects in a form of point cloud during interactions between central processing unit (CPU) threads and GPU kernels; and predicting, by a CPU host, a collision probability of any two space objects among the plurality of space objects, according to the interactions between the CPU threads and the GPU kernels.