The invention relates to a low-cost simple and convenient preparation method of 3-amino-4-methylpyridine. The method comprises the following steps: performing addition on halogenated crotonaldehyde asa raw material and nitromethane, performing methylenenation condensation, performing aminopyridine cyclization to obtain 4-methyl-3-nitropyridine, and performing reduction to prepare the 3-amino-4-methylpyridine. According to the preparation method provided by the invention, the raw materials used in the method are cheap and easy to obtain, the conditions are mild, the operation is simple, convenient and safe, the reaction selectivity is high, the product yield and purity are high, and the costs are low; and in the process, the atomic economy is high, and three waste (waste water, waste gas and solid waste) is less.