Precursor-reforming strategy induced graphitic carbon nitride (g-C 3 N 4 ) with different morphologies for enhanced photocatalytic hydrogen (H 2 ) evolution activity is highly desirable. Herein, g-C 3 N 4 microtubes (mg-C 3 N 4 ) with adjustable closure degree of microtube orifice and spatial anisotropic charge separation are established by conquering hydrogen bond during thermally exfoliate precursor. Compared to the bulk g-C 3 N 4 (bg-C 3 N 4 ) and ultrathin g-C 3 N 4 (ug-C 3 N 4 ), the tubular structure endows mg-C 3 N 4 with spatial anisotropic charge separation that accelerates transfer of charge carriers. As expected, the photocatalytic H 2 evolution (PHE) activity of mg-C 3 N 4 has been obviously enhanced. Particularly, the mg-C 3 N 4 -24 shows the best PHE activity (957.9 μmol h −1 g −1 ), which is over 18.72 and 3.77 times higher than the bg-C 3 N 4 and ug-C 3 N 4 , respectively. In addition, selective photo-deposition experiment results reveal a charge carriers migration behavior that photoproduction electrons migrate to the outer shell and holes prefer to move onto the inner shell of mg-C 3 N 4 , thus achieving efficient spatial anisotropic charge separation. We firmly believe that the work presents significant advancement for the design of other materials by precursor-reforming strategy.