Based on the coordinate transformation theory, the condition for irregular prism cloaks is deduced and the tensor expressions of electromagnetic parameters are obtained. By using the deduced tensor expressions of electromagnetic parameters, the effects of 3-sided, 4-sided and 6-sided prism cloaks are verified through full-wave simulations. The results confirm the validity of the tensor expressions of electromagnetic parameters obtained. The cloaks designed by using the deduced expressions can surely make the electromagnetic wave transmit around the inner object and resume its primary transmission direction. The work done in this paper provided a theoretical basis for the design of two-dimensional baroque cloak.