The invention provides a BPM shortwave timing signal and timing method based on Chirp signals. A timing signal is obtained by combining two Chirp base band signals with zero central frequency and opposite frequency modulation numbers through a time division mode and modulating the carrier frequency, and the timing signal is used for realizing a timing function; a receiving terminal can obtain signal measurement precision higher than that of original BPM time signals and extra anti-interference gain and then obtain more reliable timing performance. The timing signal can be compatible in an original BPM shortwave timing system without affecting users of the original system in use; the timing signal has the advantages of high multi-path fading resistance, Doppler frequency shift resistance and the like and is particularly suitable for shortwave signal channels; frequency adjusting and timing can be realized for the timing signal through simple matching and filtering without a complicatedcarrier loop or code tracking loop.