Using the extended version of Eshelby-Stroh's formulation and the method of analytical continuation, the problems of interface cracks are reduced to a Hilbert problem of vector form. A general explicit closed form solution for piezothermoelastic interface crack problem is then obtained, the whole field solutions of temperature, heat flux, displacements, electric field, stress and electric induction are given, the explicit expressions for the crack opening displacements and electric potential are also provided. A solution is obtained for the interaction problem between the interface cracks and a point heat source.