The stimulated Raman scattering (SRS) is an important method to extend the laser wavelength range. Nonlinear optical processes in gas have complex impacts on SRS laser, so it is important to make an experimental study on the relationship between the characteristic of SRS laser and gas pressure and focal length of lens for applications of SRS laser. The SRS experimental device and measurement system are introduced. Its pump source is a pulsed Nd:YAG laser at 266 nm, and active gases (H2 and D2, H2/D2 mixtures) are sealed in the 100 cm long Raman cell. The outgoing SRS laser split by a prism is measured by an energy meter for the study of SRS characteristics of the active gases. The relationship between the energy of outgoing Stokes and anti- Stokes SRS laser in the H2, D2 and H2/D2 mixtures and gas pressure and focal length of lens is presented. The laser of 12 wavelength bands from 217.84 nm to 447.15 nm are obtained, which effectively expand the scope of the application of Raman laser. The research results have very important practical application value for the use of gas SRS laser.