Abstract: In order to overcome the basic artificial firefly algorithm (Glowworm swarm optimization, GSO) in solving global optimization problems, slow convergence speed, precision is not high, easily falling into the master problem. So, The paper puts forward an improved variable step optimization algorithm. To some extent, adopt the algorithm can avoid premature mature into a local optimum, and can achieve a higher accuracy in the later. Through simulation experiment, proves that the algorithm on the convergence speed and precision are obviously improved.