A superresolution imaging technique based on wide-field stochastic fluorescent bleaching is studied. A stream of fluorescence images is simply acquired, and single fluorophore is detected by subtracting each frame from the previous one. After image subtractions, a superresolution image is got by fitting images of single fluorescent molecules with a point dispersion function method to localize them. Then this method is used to image the human embryonic kidney cells with the conventional fluorescent probe Alex 488. Compared with the conventional fluorescence microscope, the resolution increases about 40%, showing that it works with the sample with conventional fluorescent probes and can break the diffraction limit. Also it overcomes the weakness of conventional techniques based on the precise localization of single molecules, which needs to activate and quench the fluorescent molecules repeatedly, and can not be applied to conventional fluorescent samples.