Organometallic　halide　perovskites　have　expanded　promising　approaches　for　fabricating　optoelectronic　devices　with　low　cost　and　high　performance　since　their　discovery.　Here　we　propose　a　novel　technique,　flash　evaporation　printing,　to　prepare　perovskite　thin　films　with　high　quality　in　an　efficient　way,　whose　success　is　attributed　to　freestanding　carbon　nanotube　films　serving　as　the　flash　evaporator.　It　is　convenient　to　print　patterned　perovskites　using　this　method　due　to　the　compact　deposition　geometry.　The　patterned　perovskite　thin　films　were　further　manufactured　to　planar-type　photodetectors,　and　the　performance　of　the　photoelectric　devices　was　evaluated.　The　as-prepared　photodetector　shows　a　considerable　peak　responsivity　and　fast　temporal　response,　proving　flash　evaporation　printing　an　effective　route　for　exploiting　high-performance　perovskite　photodetectors,　and　this　technique　can　find　potential　applications　in　more　fields.