The invention relates to a microprism, in particular to a method for making a high-reflectance microprism reflecting film working mould with ultrasound-pulse electroforming. Electroforming liquid is prepared, namely hot water is added into an electroforming groove, then nickel sulfate hexahydrate and nickel chloride are added in sequence, hot water is added into a container, then boric acid is added, boiling is carried out, then lauryl sodium sulfate is added, after dissolution, liquid is poured into the electroforming groove, saccharin and 2-butyne-1,4-diol are added into the electroforming groove, then water is injected until the electroforming groove is full, pH is adjusted to 4.2; an anode nickel plate is placed into an anode basket and is connected to a positive electrode, a nickel master mould is connected to a negative electrode, ultrasound power is adjusted to 210-300W, frequency is adjusted to 30-50kHz, pulse current density is adjusted to 1-6A/dm<2>, current frequency is adjusted to 1000Hz, working time ratio of forward currents and backward currents is adjusted to 5:1, duty ratio is adjusted to 10%-30%, electroforming is carried out, and the high-reflectance microprism reflecting film working mould is obtained after cathode demoulding.