Cascaded all-fiber 1020 nm light source with 196 mW output power is designed and demonstrated. This light source can realize the amplification of low-power 1020 nm seed light with a cascaded amplifier. The cascaded amplifier is composed of fiber Raman amplifier and Yb3+-doped single-mode fiber amplifiers. At the stage of fiber Raman amplification, comparing experiments with three different Raman gain fiber lengths are performed to study the influence of fiber length on the output power at fixed seed power and pump power, and the spectrum of output light with 3150 m Raman gain fiber is measured. The spectrum and power characteristics of output light of Yb3+-doped single-mode fiber amplifiers are studied. This 1020 nm light source provides pump source for the study of the tandem pumping of 1064 nm fiber laser. And this cascaded all-fiber amplification solution based on fiber Raman amplification can be used to amplify other special seed light at low power.