The genetic optimization algorithm method is used to design rotary compressors with sliding vanes. After the air properties, volume segment, compression power, loadings and stresses of vanes, friction forces and power loss are calculated, the objective function of the maximum efficiency and the constrained conditions can be derived and integrated. Using the ambient air conditions and the properties of Vespel, the effects of the mutation rate, crossover rate and population size of the genetic algorithm on the design parameters are studied. These design parameters include the major axis length, minor axis length, angular locations of inlet and outlet ports and rotational speed of the compressor, the thickness, depth and height of vanes, and the polytropic exponent. The efficiency of the compressor increases to 0.55 compared with the value of 0.4 obtained from the existing data.