Opportunistic array radar(OAR) is a new generation radar system based on the stealth of the platform,which can improve the modern radar performance effectively.Designing the orthogonal code sets with low autocorrelation and cross-correlation is a key issue for OAR.This paper proposes a novel hybrid genetic algorithm(HGA) and designs the polyphase orthogonal code sets with low autocorrelation and cross-correlation properties,which can be used in the OAR system.The novel algorithm combines with simulated annealing(SA) and genetic algorithm(GA),adds in keeping best individuals and competition in small scope,and introduces grey correlation evaluation to evaluate fitness function. These avoid the premature convergence problem existed in GA and enhance the global searching capability.At last,the genetic results are optimized to obtain the best solution by using greedy algorithm.The simulation results show that the proposed algorithm is effective for the design of orthogonal phase signals used in OAR systems. Opportunistic array radar (OAR) is a new generation radar system based on the stealth of the platform, which can improve the modern radar performance effectively. Designing the orthogonal code sets with low autocorrelation and cross-correlation is a key issue for OAR.This paper Novel hybrid genetic algorithm (HGA) and designs the polyphase orthogonal code sets with low autocorrelation and cross-correlation properties, which can be used in the OAR system. The novel algorithm combines with simulated annealing (SA) and genetic algorithm (GA) , adds in keeping best individuals and competition in small scope, and introduces grey correlation evaluation to evaluate fitness function. in GA and enhance the global searching capability. At last, the genetic results are optimized to obtain the best solution by using greedy algorithm. The simulation results show that the proposed algorithm is effective for the design of orthogonal phase signals use d in OAR systems.