Abstract: A battery fault diagnosis method includes: A vehicle uploads a collected first original data set to a cloud BMS. The cloud BMS preliminarily diagnoses a battery based on the first original data set and sends a risk warning to the vehicle based on the preliminary diagnosis for the battery. The vehicle obtains a second original data set based on the received risk warning. The second original data set is obtained from the vehicle through collection. Data items included in the second original data set are more than data items included in the first original data set or a data collection frequency of the second original data set is higher than a data collection frequency of the first original data set. The vehicle and/or the cloud BMS deeply diagnose/diagnoses the battery based on the second original data set, to determine a fault level of the battery.