Scintillation Detector has been playing an important role in radiation detection. The methods to improve the spatial resolution of scintillation detector have been widely studied. Commonly used scintillation detectors often use photon sensors attached to a scintillator to detect the position of light source in the scintillator, normally by counting the number of photons. In these cases the spatial resolution can reach about 1 mm. However some medical applications like positron emission tomography (PET) requires higher resolution. Some application-specific types of scintillation detector such as Si/CdTe Compton camera and PET crystal cube have improved the spatial resolution to about 250 μm to 500 μm [1]. However, the resolution of these types of scintillation detectors are mainly restricted by their hardware size. Therefore further improvement in the resolution can hardly be achieved unless the hardware has an obvious scale down. This paper introduces a method of high resolution point light source detection in scintillator by offering a scintillation detector with a new structure. Compared to the typical scintillator detector, the proposed one introduces a lightproof material with pinholes between the scintillator cube and photon sensors, which we used single-photon avalanche diodes (SPADs). Based on this novel construction the light source can be detected through photon reverse ray tracing method. The proposed scintillation detector can provide high spatial resolution about 10 μm ∼ 20 μm, which is more than ×10 finer than the prior arts.