A power control method, comprising: receiving (402, 403), by a second terminal device, a first signal and an indication information from a first terminal device, wherein the first signal comprises a first physical sidelink shared channel, PSSCH; determining, by the second terminal device, a path loss estimate between the first terminal device and the second terminal device based on the indication information and the received power of the first signal; determining, by the second terminal device, a transmit power of a second signal based on the path loss estimate between the first terminal device and the second terminal device and a path loss estimate between a network device and the second terminal device; sending, by the second terminal device, the second signal to the first terminal device based on the transmit power of the second signal; wherein, the second signal is a second PSSCH, the transmit power of the second PSSCH is: P PSSCH = min[ P PSSCH,MAX, 10log 10 (2 μ × M PSSCH) + P O_PSSCH,1 + α PSSCH,1 × PL SL, 10log 10 (2 μ × M PSSCH) + P O_PSSCH,2 + α PSSCH,2 × PL DL] wherein P PSSCH,MAX is a maximum transmit power of the second PSSCH, μ is the numerology of the second PSSCH, M PSSCH is bandwidth of the second PSSCH, P O_PSSCH,1 is a target receive power of the second PSSCH, α PSSCH, 1 is a first path loss compensation factor of the second PSSCH, PL SL is the path loss estimate between the first terminal device and the second terminal device, P O_PSSCH,2 is a target receive power of the first PSSCH, α PSSCH, 2 is a second path loss compensation factor of the second PSSCH, PL DL is the path loss estimate between the network device and the second terminal device; wherein the second terminal device obtains a transmit power of the first signal based on the indication information; wherein the indication information is used to indicate or include a first value, where the first value is a value in a reference value set, the reference value set includes at least two power values, the first value does not exceed a first power, and the first power is determined according to a maximum transmit power of the first signal. receiving (402, 403), by a second terminal device, a first signal and an indication information from a first terminal device, wherein the first signal comprises a first physical sidelink shared channel, PSSCH; determining, by the second terminal device, a path loss estimate between the first terminal device and the second terminal device based on the indication information and the received power of the first signal; determining, by the second terminal device, a transmit power of a second signal based on the path loss estimate between the first terminal device and the second terminal device and a path loss estimate between a network device and the second terminal device; sending, by the second terminal device, the second signal to the first terminal device based on the transmit power of the second signal; wherein, the second signal is a second PSSCH, the transmit power of the second PSSCH is: P PSSCH = min[ P PSSCH,MAX, 10log 10 (2 μ × M PSSCH) + P O_PSSCH,1 + α PSSCH,1 × PL SL, 10log 10 (2 μ × M PSSCH) + P O_PSSCH,2 + α PSSCH,2 × PL DL] wherein P PSSCH,MAX is a maximum transmit power of the second PSSCH, μ is the numerology of the second PSSCH, M PSSCH is bandwidth of the second PSSCH, P O_PSSCH,1 is a target receive power of the second PSSCH, α PSSCH, 1 is a first path loss compensation factor of the second PSSCH, PL SL is the path loss estimate between the first terminal device and the second terminal device, P O_PSSCH,2 is a target receive power of the first PSSCH, α PSSCH, 2 is a second path loss compensation factor of the second PSSCH, PL DL is the path loss estimate between the network device and the second terminal device; wherein the second terminal device obtains a transmit power of the first signal based on the indication information; wherein the indication information is used to indicate or include a first value, where the first value is a value in a reference value set, the reference value set includes at least two power values, the first value does not exceed a first power, and the first power is determined according to a maximum transmit power of the first signal.