The invention publishes a method on power control by the channel quality, which includes: obtain signal-to-noise ratio according to the quality of upward channel feedback channel; obtain signal-to-noise ratio of before de-spread according to the signal-to-noise ratio's relations between the signal before de-spread and the signal after de-spread; obtain signal-to-noise ratio of pilot frequency channel according to relation between the signal before de-spread and the goal channel's power. After carrying on simulation to this goal channel, obtain the target value of satisfy signal-to-noise ratio; obtain goal channel's power according to the relation between signal-to-noise ratio and target value of the goal channel. This method improves the channel's transmission quality to ensure the transmission reliability.