Preparation methods of papaverine and papaverine hydrochloride

The invention discloses a preparation method of papaverine. The preparation method comprises 1, dissolving 3, 4-dihydropapaverine hydrochloride in water and adjusting pH of the solution to greater than 7, 2, through trimethylbenzene, carrying out extraction on the aqueous solution obtained through the step 1, and 3, adding a dehydrogenation reaction catalyst into the obtained organic phase, carrying out a dehydrogenation reaction process at a temperature of 50-180 DEG C and then treating the product to obtain papaverine. The invention also discloses a method for preparing papaverine hydrochloride from the papaverine. Through use of trimethylbenzene as a dehydrogenation reaction solvent, a dehydrogenation reaction temperature is reduced, peroxide production is avoided and production safety is greatly improved. The preparation method realizes recycle of trimethylbenzene and reduces a production cost of papaverine or papaverine hydrochloride.