Abstract: An opening loop control system of high-precision laser wavelength output of BBO optical parametric oscillation tuning system with American General Scanning Inc.'s controller to control BBO crystal's rotation is realized.The control system's relative wavelength tuning error is less than 0.04%.We also demonstrated 0.347μm laser pumped type-Ⅰ phase matching BBO optical parametric oscillation's theoretical and experimental curve of output wavelength vs incident angle of pump light.