The present disclosure relates to a slit grating, a method for manufacturing the same and a display device. The slit grating includes an upper substrate, a lower substrate, an electric-controlled dielectric layer and a liquid composite layer arranged between the upper substrate and the lower substrate. The liquid composite layer consists of a light-shielding liquid and a light-transmitting liquid incompatible with each other. The electric-controlled dielectric layer has an electrically-induced light-shielding-liquid-philic or light-shielding-liquid-phobic property. According to the present disclosure, a liquid crystal layer is replaced with the liquid composite layer consisting of the light-shielding liquid and the light-transmitting liquid incompatible with each other, and the distribution of the light-shielding liquid and the light-transmitting liquid is controlled by means of the electrically-induced light-shielding-liquid-philic or light-shielding-liquid-phobic property of the bar-like electric-controlled dielectric sublayers, so as to achieve the switch between a 2D display mode and a 3D display mode. Due to the absence of polarizers desired for the liquid crystal slit grating, it is able to improve the light utilization rate. Moreover, as compared with the liquid crystal slit grating, for the slit grating of the present disclosure, there is less demand on a liquid material layer and a cell thickness, so it is able to simplify the manufacturing process.