In recent years, metal phosphides (MPs) have aroused much concern due to their ideal performance in catalysis. In this work, we design a family of two-dimensional (2D) MPs (M = Co, Ge, and Sn) and investigated their structural, ferroelectric (FE), magnetic and catalytic properties based on first-principles calculations. We find that CoP is stable with multiferroic behaviors, which can be explained by the Pseudo Jahn-Teller distortion (PJTE) mechanism. With electrochemical stability, non-noble CoP realizes the overpotentials of 0.27 and 0.014 V for oxygen evolution reaction (OER) and nitrogen monoxide reduction reaction (NORR), respectively. The adsorption of NO is attributed to the concept of “pseudo-inert”. Our work reveals the intrinsic multiferroicity and catalytic performance of 2D CoP, which may provide a guidance on the design of 2D functional materials for multiple applications.