Folded cascode and Class AB topology (FC-AB) operational amplifiers are widely studied and used. However, it is still difficult for designers to build up a specific operational amplifier quickly and accurately due to various applications. In order to solve this problem, this paper presents a quasi-standard design procedure of operational amplifiers for designers who can complete the circuit design by following this procedure. Current distribution was determined as the starting point and the adjustable point in this design procedure, and the most concerned parameter was set as primary constraint and optimized through multiple iterations. At last, the sizes of devices were obtained by corresponding current and trans-conductance. The design procedures for low noise operational amplifiers have been presented in the form of flow charts. The average error between the theoretical values and the final design values of key device sizes were 11.48%. To verify the feasibility of the design procedure, an operational amplifier was designed by using this design procedure and fabricated with a standard 0.18 μm CMOS process. The concerned electrical characteristics are all met with the design requirements. Its input-referred noise is 10.8 nV/√Hz, which differs from the target value by only 1.8%.