The present invention discloses a data sending method, device and system. After establishing a connection between a wireless terminal and a wireless network side, it is detected whether the wireless terminal has data to be sent to the wireless network side. The data to be sent includes signaling data or user data. If a result of the detecting is that the wireless terminal does not have data to be sent, a power amplifier of the wireless terminal is confirmed to be in a non-working state. If a result of the detecting is that the wireless terminal has data to be sent, a power amplifier of the wireless terminal is confirmed to be in a working state.