1. A microlens array imaging device, comprising: a main lens; a microlens array containing a plurality of microlenses arranged in an array; and an image acquisition unit configured to acquire images projected by the microlens, wherein, the main lens projects a first image of an object for the plurality of microlenses, each of which projects a second image of the first image on the image acquisition unit; each second image includes an image circle and a circle of confusion around the image circle; and a distance between an image circle of one microlens and an image circle of an adjacent microlens is equal to or greater than a summation of a radius of the second image corresponding to the one microlens and a radius of the image circle of the adjacent microlens, and is equal to or less than a summation of the radius of the second image corresponding to the one microlens and a radius of the second image corresponding to the adjacent microlens.