The interreaction between laser pulses and molecules is the key point of researching photochemical reactions, it is also an important issue of laser control of chemical reactions. A model for realistic parallel simulations of photochemical reactions induced by an ultrashort laser pulses is developed. In this model, the electrons are coupled to the vector potential of the radiation field through the time-dependent Peierls substitution. The interaction between laser pulses and molecules is unambiguously. The simulation program is realized. It is proved that the simulation program can repeat the experiments of photochemical reactions and provides many details that could not be observed experimentally by comparing the simulations with the experimental results of photodissociation of cyclobutane and C60. The efficiency of the program is improved by parallel design， and tested on super computer system, the result shows that the parallel program can simulate the photochemical reactions high-efficiently and provide information for controlling the photochemical reactions.