The invention provides a navigation signal modulation method which comprises the following specific steps: multiplying an upper sideband and lower sideband data path difference signal by a sine binary system subcarrier to obtain a Q branch odd time slot baseband signal; multiplying an upper sideband and lower sideband data path sum signal by a cosine binary system subcarrier to obtain a data pathI branch odd time slot baseband signal; multiplying an upper sideband and lower sideband pilot frequency path difference signal by the sine binary system subcarrier to obtain a Q branch even time slot baseband signal; multiplying an upper sideband and lower pilot frequency path sum signal by the cosine binary system subcarrier to obtain an I branch even time slot baseband signal; and carrying outQPSK (Quadrature Phase Shift Keying) modulation on the I and Q branch baseband signals to obtain a TD (Time Division)-AltBOC modulation signal. According to the navigation signal modulation method, different navigation services can be transferred between two adjacent frequency bands, each navigation business comprises a data path and a pilot frequency path, and the navigation signal of each subband can be independently received, and the upper sideband signal and lower sideband signal can be received jointly to obtain high-precision navigation performance.