A projection display apparatus and a control method therefor. The projection display apparatus comprises: a spatial light modulation device; a light emitting device capable of emitting sequential light, the sequential light comprising at least one type of sequential laser and at least one type of sequential fluorescence, and at least one type of first laser in the at least one type of sequential laser having spectral overlap with at least one type of first fluorescence in the at least one type of sequential fluorescence; and a control device connected to the spatial light modulation device. The control device comprises a first control unit used for converting at least one primary color image signal, in a decoded source image signal, corresponding to the first laser and the first fluorescence that have spectral overlap into a first primary color control signal and a second primary color control signal, and controlling the spatial light modulation device using the first primary color control signal and the second primary color control signal to modulate the first laser and the first fluorescence respectively. The method can improve the luminous efficacy of the first fluorescence and the first laser, thereby improving the brightness of the projection display apparatus.