The invention belongs to the technical field of oil exploitation and particularly relates to a calculation method for predicating recovery percentage and water cut of an oil field. The method for predicting the recovery percentage and water cut of the oil field comprises the following steps of: (1) obtaining a water-oil mass ratio: Qw/Qo, i.e. Fg; (2) obtaining the initial oil saturation: Soi; (3) testing the irreducible water saturation: Swi; (4) obtaining a crude oil volume factor Bo; (5) putting the above parameters into a formula as shown in the specification so as to obtain a relationship between the water cut and the recovery percentage. According to the method for predicting the recovery percentage and water cut of the oil field provided by the invention, a universal method applicable to water-flooding development of reservoirs with high-permeability, low-permeability and ultra-low permeability is obtained, and the actual changing rule of the water cut and recovery percentage of reservoirs and the percolation characteristic representation of the oil reservoirs of different types can be reflected, therefore the method is fit for the practical situation better; furthermore, the development index prediction precision can be improved, therefore the method has an important practical significance on the production practice of the oil fields.