An apparatus for controlling transmit power of user equipment, comprising: a calculation module, configured to: when total uplink transmit power of user equipment, UE, exceeds maximum allowed transmit power, calculate a first gain factor according to the maximum allowed transmit power; a processing module, configured to perform quantization processing on the first gain factor according to a gain factor of a first physical channel, to obtain a second gain factor, wherein the first physical channel comprises a dedicated physical control channel 2, DPCCH2; and a reduction module, configured to reduce a gain factor of a second physical channel to the second gain factor, to reduce transmit power of the second physical channel, so that the total uplink transmit power of the UE does not exceed the maximum allowed transmit power, wherein the second physical channel comprises a high speed dedicated physical control channel, HS-DPCCH; characterized in that, the processing module comprises: a processing unit, configured to: if a second ratio is greater than or equal to a smallest value among multiple preset quantitative ratios, perform quantization processing on the first gain factor according to the gain factor of the first physical channel and the multiple preset quantitative ratios, to obtain the second gain factor, so that a first ratio is a greatest preset quantitative ratio that does not exceed the second ratio among the multiple preset quantitative ratios, wherein the first ratio is a ratio between the second gain factor and the gain factor of the first physical channel, and the second ratio is a ratio between the first gain factor and the gain factor of the first physical channel; and a setting unit, configured to: if the second ratio is less than the smallest value among the multiple preset quantitative ratios, set the second gain factor to 0, wherein the setting unit comprises: a setting subunit, configured to: if the second ratio is less than the smallest value among the multiple preset quantitative ratios and a current timeslot of the UE is a timeslot that is used to transmit channel quality indicator, CQI, information of the second physical control channel, set the second gain factor to 0. a calculation module, configured to: when total uplink transmit power of user equipment, UE, exceeds maximum allowed transmit power, calculate a first gain factor according to the maximum allowed transmit power; a processing module, configured to perform quantization processing on the first gain factor according to a gain factor of a first physical channel, to obtain a second gain factor, wherein the first physical channel comprises a dedicated physical control channel 2, DPCCH2; and a reduction module, configured to reduce a gain factor of a second physical channel to the second gain factor, to reduce transmit power of the second physical channel, so that the total uplink transmit power of the UE does not exceed the maximum allowed transmit power, wherein the second physical channel comprises a high speed dedicated physical control channel, HS-DPCCH; characterized in that, the processing module comprises: a processing unit, configured to: if a second ratio is greater than or equal to a smallest value among multiple preset quantitative ratios, perform quantization processing on the first gain factor according to the gain factor of the first physical channel and the multiple preset quantitative ratios, to obtain the second gain factor, so that a first ratio is a greatest preset quantitative ratio that does not exceed the second ratio among the multiple preset quantitative ratios, wherein the first ratio is a ratio between the second gain factor and the gain factor of the first physical channel, and the second ratio is a ratio between the first gain factor and the gain factor of the first physical channel; and a setting unit, configured to: if the second ratio is less than the smallest value among the multiple preset quantitative ratios, set the second gain factor to 0, wherein the setting unit comprises: a setting subunit, configured to: if the second ratio is less than the smallest value among the multiple preset quantitative ratios and a current timeslot of the UE is a timeslot that is used to transmit channel quality indicator, CQI, information of the second physical control channel, set the second gain factor to 0. a processing unit, configured to: if a second ratio is greater than or equal to a smallest value among multiple preset quantitative ratios, perform quantization processing on the first gain factor according to the gain factor of the first physical channel and the multiple preset quantitative ratios, to obtain the second gain factor, so that a first ratio is a greatest preset quantitative ratio that does not exceed the second ratio among the multiple preset quantitative ratios, wherein the first ratio is a ratio between the second gain factor and the gain factor of the first physical channel, and the second ratio is a ratio between the first gain factor and the gain factor of the first physical channel; and a setting unit, configured to: if the second ratio is less than the smallest value among the multiple preset quantitative ratios, set the second gain factor to 0, wherein the setting unit comprises: a setting subunit, configured to: if the second ratio is less than the smallest value among the multiple preset quantitative ratios and a current timeslot of the UE is a timeslot that is used to transmit channel quality indicator, CQI, information of the second physical control channel, set the second gain factor to 0.