Abstract: Using the complex-variable function knowledge, half-inverse method and undetermined coefficient method, the problem about piezoelectric composite material with collinear periodic cracks was investigated. The analytical solutions of the stress, electric displacement, the stress field intensity factor, electric displacement intensity factor and mechanical stain energy release rate were given explicitly with the assumption that the surface of the crack was electrically impermeable. When the distance of adjacent cracks tended to infinite, collinear periodic of cracks degenerated into a single crack, piezoelectric composite material with a single crack results was obtained. Numerical examples were given to discuss the influences of the length of the collinear periodic cracks, the distance of adjacent cracks of the collinear periodic cracks and the electromechanical loads on the mechanical stain energy release rate. The results show that mechanical stain energy release rate enhances as the length of collinear periodic cracks, the distance of adjacent collinear periodic cracks, mechanical loading, positive electric field increase, however, mechanical stain energy release rate reduces as the negative electric field increases.