In order to reconstruct the sound field of target sources in non-free sound field, a method of sound field separation and reconstruction is presented based on spatial resampling with single layer microphone array. In this method, the spherical harmonics are taken as the basis functions, and the spherical harmonics of different orders are added to describe the mathematical model of the sound field. On the basis of the nearfield acoustic holography, the coefficients of the basis functions can be obtained with two groups' sound pressures resampled from the microphone array, then the sound fields generated by the sound sources on both sides of the microphone array are separated. The mathematical model is validated against the benchmark values. A non-free sound field with a radially oscillating sphere and a transversely oscillating rigid sphere is built, and the impact of various parameters such as the signal to noise ratio, the geometric shape and area of the microphone array, location of target sound source, and frequency of signals on the accuracy of separation is examined. Finally, some suggestions are given for the industrial application of the above method.