Abstract: The conversion of residue number system to binary system using traditional mixed radix conversion lacks of parallelism. An improved mixed radix conversion is proposed. A residue to binary(R/B) conversion circuits based on moduli 2n,2n-1,2n+1-1,2n-1-1 is studied and designed. The modulo 2n-1 adder has a relatively simple implementation, in which the design of the circuit is to avoid the introduction of read-only memory and time sequence circuit, and the R/B conversion circuit is implemented by a simple combination of logic and adder cascade. The analysis results show that the reverse converter shortens the delay of critical path and decreases the power dissipation efficiently. Compared to those R/B converters with same dynamic range designed in recent years, the circuit designed in this paper has a better performance advantage apparently.