A LD end pumped solid-state,single longitudinal mode 561 nm yellow laser is reported.In this study,the narrowband reflective film is applied to refrain start-up gain of three long wavelengths.Intracavity frequency doubling of class I critical phase matching LBO for the fundamental beam 1123 nm and V cavity structure are designed to get a single wavelength operation.F-P etalon frequency selection method is further used to obtain a stable single longitudinal mode output of 561 nm.When the pump power is 2.4 W,laser power of 80 mW is obtained;light-light conversion efficiency is 3.3% and longitudinal mode line-width is 24.1 MHz.The laser has high practical value in the biomedical field such as light source of the eye macular disease therapeutic apparatus and flow cytometry,etc.,and it has been one of research hotspots for all solid-state lasers in recent years.