The invention relates to a method for preparing acetylene through partial oxidation of hydrocarbons. According to the method, mixed gas of methanol purge gas and natural gas is adopted as raw material gas, and acetylene and synthetic gas are prepared through preheating, mixing and reacting the mixed raw material gas with oxygen gas; the methanol purge gas accounts for 1-50% of the mixed raw material gas in percentage by volume; and when the volume percent of the methanol purge gas in the mixed raw material gas is 30-50%, the mixing temperature of the mixed raw material gas and the oxygen gas is controlled to be 400-550 DEG C, and the mixing temperature of the mixed raw material gas and the oxygen gas is controlled to be 550-620 DEG C when the volume percent of the methanol purge gas in the mixed raw material gas is 1-30%. The method disclosed by the invention has the advantages that the production is carried out stably and safely, the acetylene yield and methane conversion ratio are effectively increased simultaneously, the production of carbon black and higher hydrocarbons is reduced, and the requirements of devices for the change of raw material gas ingredients are met; and the mixed raw material gas of the natural gas and the methanol purge gas is adopted, and the methane content of the mixed raw material gas can be decreased to 50%, so that the production cost is reduced greatly.