Aiming at the Quantum Genetic Algorithm′s shortcomings in the target edge detection in an image,an improved measure is proposed.At first,the quantum bits′ conversion is implemented to control the transformation and delivery of the evolution of quantum states.And additional factors are added to the rotation angle of quantum gates to control the convergence speed.And adjustment factor is introduced to the rotation direction to avoid too large population and too small angle change of direction;then quantum bit rate is coded to make the probability of gene locus to be same.Finally,the edge detection is processed.Simulation results show that the algorithm is more effective for image edge detection.