A telescopic pump nozzle for a pump includes a shaft having a first end and a second end, a channel formed therein and communicating the first end with the second end, and a threadedly coupled portion defined at the first end, and in addition, the second end is coupled to an air pipe of the pump. A tube has a first end and a second end and includes first and second connected sections formed on the inner wall of the first end, a compartment defined in the second end, and at least one O-ring mounted on the shaft and abutted against the inner wall of the compartment in an air-tight manner. The second connected section is provided between the first connected section and the compartment. The shaft is slideably disposed in the compartment of the tube. The threadedly coupled portion is selectively coupled to the second connected section.