A power adjusting method and apparatus provided by embodiments of the present invention relate to the field of communications. The power adjusting method of this embodiment includes: receiving a signal from a sending end, where the signal includes a cyclic prefix (CP) signal; detecting and acquiring first receiving power and second receiving power of the CP signal, where the first receiving power is average power of N sampling points of the CP signal, and the second receiving power is average power of M sampling points of the CP signal; after determining that a ratio of the first receiving power to target power is greater than a first preset threshold, adjusting signal power magnification; and after determining that the ratio of the second receiving power to the target power is greater than a second preset threshold, adjusting the signal power magnification again.