The invention discloses a deslagging agent for lead alloy smelting. The deslagging agent comprises sodium nitrate and wood charcoal powder; the deslagging agent at least also comprises potassium permanganate and / or pyritic ash; the deslagging agent for lead alloys is formed by mixing the potassium permanganate and / or the pyritic ash with the sodium nitrate, wood charcoal powder and other deslagging agent components; through the potassium permanganate component, oxygen can be decomposed at a temperature of a melting point of lead and oxidation reaction on the oxygen and the wood charcoal is carried out, and a large amount of heat is produced to ensure that a temperature of a melting agent is quickly raised to reach a decomposition temperature of the sodium nitrate, and the sodium nitrate isfurther decomposed and the oxygen is released, and then oxidation reaction on the oxygen and the wood charcoal is carried out, so that a large amount of heat is produced, a slag temperature is further raised, and separation of slag and lead liquid is promoted; by adding the pyritic ash, copper harmful elements can be further removed in a smelting process.