A peak frequency stabilized transverse zeeman He-Ne laser is reported in this paper. As a result of experiments we found that the maximum value of the laser's beat frequency of the vertical vibration corresponds to the centre of gain profile of the laser. Based on this specific property, the laser frequency can be stabilized at the centre of gain profile. Comparing with the iodine absorbing stabilized frequency standard laser national standard by the method of beat frequency, we found the frequency stability of this laser is 1×10-9 and it can work continuously over eight hours.