The invention discloses a technology for preparing fruit juice powder from passion fruits as raw materials. The technology comprises removing shells and seeds of selected and cleaned fresh passion fruits, beating the fresh passion fruits to obtain passion fruit raw pulp with soluble solid content of 10-12 brix degrees, total acid content of 3-5% and pH of 3.0+/-0.5, carrying out freeze concentration on the passion fruit raw pulp to obtain thick paste with soluble solid content of 40-60 brix degrees, freezing the thick paste to a temperature of -50 to -60 DEG C, after freezing of all the thick paste, feeding the thick paste into a crusher, carrying out crushing so that particle diameter is less than 3mm, putting the crushed thick paste on a disc, putting the disc with the crushed thick paste into a drying tank, carrying out pressurization, carrying out freezing at a temperature of -29 to -23 DEG C, keeping the temperature for 3-6h, gradually heating the dried material to a temperature of 27 DEG C in 1-2h, carrying out heating again, keeping the temperature of 50-60 DEG C for several minutes, carrying out milling by a jet mill, collecting the aggregate which is fruit juice powder and carrying out packaging so that the passion fruit juice powder product with water content less than 4.5% is obtained. The juice powder retains nutrients, can be stored at a normal temperature for a long time, is free of dextrin and any antiseptic, has light weight, can be carried and transported easily, has a wide application range and is simple and convenient in use.