The present invention discloses a passion fruit juice and a preparation method thereof. The preparation method includes the following steps: selecting and washing passion fruits, air-drying, conducting a first freezing, steaming fruits, conducting a second freezing, peeling, thawing, pulping and filtering, and seasoning and filling. By conducting a combined technology of air-drying, freezing, fruit steaming and freezing, an efficient method for removing the skins of passion fruits is achieved, and by using the middle skins, inner skins, pulp and juice of passion fruits, the fruit juice which is sour, sweet, tasty, and rich in nutrition is obtained; and the production method is simple, economical and environmentally friendly, suitable for large-scale industrialized production, and relatively low in production costs.