The invention discloses a titanium doped C3N4 catalyst and a preparation method and application thereof. The preparation method includes: dropwise adding a titanate solution into a melamine solution,and then drying the solvent through distillation to obtain a precursor; performing thermal treatment on the precursor to obtain the titanium doped C3N4 catalyst, wherein during the thermal treatment,rising the temperature to 350-600 DEG C at the speed of 1-10 DEG C/minute, and keeping the temperature for 0.5-4 hours. The titanium doped C3N4 catalyst has the advantages that the catalyst uses oxygen as the oxygen source and has high catalytic activity and extremely high product selectivity in the epoxidation reaction of various olefins under mild conditions; the titanium doped C3N4 catalyst issimple in preparation method, low in preparation cost, mild in reaction conditions, excellent in cycle performance and the like.