In this paper, a new family of Cassinian wave-guides is proposed, simulating and calculation are finished with CST Microwave Studio that based on Finite Integral Technique (FIT), and some results are given. Electromagnetic field mode type of it is TE, electromagnetic field is stronger near neck region, and some resonance frequencies appear. The new Cassinian curve wave-guides will possess higher power than ones of the rectangular and elliptic wave-guides because the height at the position where maximal electric field occurs is smaller.