The transparency and second harmonic properties of Al,S and Te doped GaSe crystals were studied.Low absorption coefficients of α≤0.1～0.2 cm-1 are found in crystals with suitable doping level in transparent range which can be used in nonlinear devices.High doping level is allowed in GaSe:S crystals whose transparency spectra shift towards to short-wavelength range.The short wavelength transparency cut-off of both Al and Te doped crystals shifts more slowly than S doped crystals towards to opposite direction.The optical quality of the crystals has declined markedly when the doping concentration up to GaSe:Al (0.5 mass%) and GaSe:Te (5 mass%).The phase matching curves shift towards to short-wavelength and output power is significantly higher in S doped GaSe crystals than that in pure GaSe crystals with fs Ti:Sapphire laser and CO2 laser pumping.The optimal doping concentration is ascertained as 2 mass%.No obvious differences of type I second harmonic phase matching angle between Al,Te doped and pure crystals are found.The experimental results are in good agreement with theoretical curve.GaSe:Te crystals are found to possess the hexagonal structure like ε-GaSe when the doping concentration is no more than 5 mass% with nonlinear method.The SHG efficiency ratio of the optimal doped crystals GaSe:Al (0.1 mass%),GaSe:S (2 mass%) and GaSe:Te (0.5 mass%) is about 1:0.6:0.5 under CO2 laser pumping.GaSe:S (2 mass%) crystal shows the best performance whose efficiency is about 3 times higher than that in pure GaSe among all used samples.