A power and signal transmission method for a wireless lamp including a lamp body and a lamp holder. The power and signal transmission method includes: S01: inputting a current to a power supply module of the lamp holder and inputting a control signal to the lamp holder and converting the control signal into a pulse control signal; S02: integrating each signal segment of the pulse control signal into a high-frequency signal with a preset frequency; S03: outputting carrier signal to the lamp body; S04: receiving the carrier signal, generating and outputting power to an LED drive module and a lamp body control module; S05: extracting the carrier signal, and outputting the carrier signal to the lamp body control module; S06: extracting the control signal from the pulse control signal; S07: correspondingly outputting a PWM signal to the LED drive module; and S08: driving the lamp to change light emitted therefrom.