in order to ensure the safety in complex conditions of reinforced concrete water tower demolition blasting collapse in the process, before the official blasting demolition using computer digital simulation becomes more and more important. Was described in this paper based on the ANSYS / LS-DYNA software platform, tower of 20 m high reinforced concrete structure under complex environment simulation the blasting collapsing process, through the model establishment, calculation and post treatment process, can clearly see after the water tower in the simulation of collapse process of collapse angle and the collapse of accumulation length and time course of the changes and matches well with the simulated results and the practical engineering.