In order to improve the Raman scattering intensity of a trace gas, a cavity-enhanced Raman spectroscopy (CERS) technique with injection locking was introduced. A diode laser input (638 nm, 15 mW) was coupled into a V-shaped enhanced cavity composed of three highly reflective mirrors. Using the injection locking technique, an intracavity laser beam was generated and enhanced by a factor of 500 to obtain a power of 7.5 W. The Raman spectra of the individual trace gases and the mixture were obtained. According to the principle of Raman spectrum peak selection and a signal-to-noise ratio greater than 3, the characteristic Raman peaks of H2, CO, CO2, CH4, C2H6, C2H4, and C2H2 are determined as 4 156, 2 143, 1 388, 2 918, 2 955, 1 344, and 1 975 cm-1, respectively, and the limits of detection are determined as 10.2, 21.7, 9.4, 2.1, 8.9, 4.9, and 3.3 Pa. Trace homonuclear diatomic gases and mixed gases can thus be detected simultaneously using a single-wavelength diode laser and CERS. Therefore, CERS has the potential to become an alternative optical technology for gas detection.