Drotaverine hydrochloride crystal form III and crystal form IV and preparation method thereof

The invention discloses drotaverine hydrochloride poly-crystal forms, which are respectively a crystal form III and a crystal form IV. The crystal form III shows characteristic peaks on places of 3.985 DEG, 7.969 DEG, 8.959 DEG, 10.459 DEG, 15.965 DEG, 17.011 DEG, 22.181 DEG, 23.346 DEG and 24.548 DEG in an X-ray powder diffraction spectrogram represented by a diffraction angle of 2 theta+/-0.2 DEG; the crystal form IV shows characteristic peaks on places of 4.164 DEG, 8.288 DEG, 8.939 DEG, 11.465 DEG, 15.866 DEG, 16.596 DEG, 22.261 DEG and 24.076 DEG. The invention further discloses a preparation method of the crystal forms. Water is directly adopted as a crystallization solvent for the crystal form III and the crystal form IV disclosed by the invention; the stability is better; the preparation method is simple.