In this paper, we investigate KP equation by the Hirota bilinear method and obtain its bilinear form successfully. On the basis of above bilinear form, a number of explicit solutions including one-solitary wave solution, two-solitary wave solution and their generalized form N-solitary wave solution are obtained successfully. Moreover, in view of the homoclinic breather limit method, we also express breather wave solutions and rogue wave solutions of KP-equation. Finally, with mathematical software Maple, we obtained overhead views, perspective views and wave propagation pattern of solutions in different parameter areas.