In order to meet the application requirements of the frequency-stabilized lasers and make the laser frequency be freely locked in a certain range, a tunable laser stabilized to Fabry-Pérot (F-P) cavity using the Pound-Drever-Hall (PDH) technique was proposed. The laser frequency was locked on the F-P cavity by means of direct modulation of the laser current. The results show that, the fractional frequency instability turns out to be 5.3×10^?12@1 s averaging time by analyzing the beat frequency from two identical lasers, which is three orders of magnitude better than free running. The linewidth of the stable laser is 381.68 kHz@10 μs and the 12 h power stability is 1.7×10^?3. By controlling the F-P cavity length, the continuous tuning can be achieved over a range greater than 1.2 GHz and the tuning factor is 401.7 kHz/mV. The frequency-stabilized laser can reach the application target and its continuous tuning characteristics can effectively compensate for the limitation of the absorption cell as the frequency reference.