The invention relates to the technical field of seat cushions, in particular to a semiconductor cooling and heating automobile seat cushion and a temperature adjusting method. A semiconductor cooling and heating automobile seat cushion comprises a temperature adjusting main machine and a temperature adjusting seat cushion. The temperature adjusting host comprises a shell, and a refrigerating system, a water pump, a water tank and a temperature adjusting control unit which are arranged in the shell; the refrigerating system comprises a radiator, a semiconductor refrigerating device and a water cooling head, the semiconductor refrigerating device is provided with a first end face and a second end face which are oppositely arranged, the first end face of the semiconductor refrigerating device is attached to the water cooling head, and the second end face of the semiconductor refrigerating device is attached to the radiator. According to the semiconductor cooling and heating automobile seat cushion, the temperature of the automobile seat cushion can be rapidly adjusted, automatic control and manual control over the temperature of the automobile seat cushion are achieved, a user can conveniently conduct adaptive adjustment on the temperature of the seat cushion according to the condition of the user, and the semiconductor cooling and heating automobile seat cushion can meet the requirements of different users.