A three-dimensional image sensing system, comprising: a light-emitting module, configured to emit incident light to a target object; and a photosensitive module, configured to receive reflected light of the incident light upon being reflected by the target object, wherein the photosensitive module comprises: a condenser lens, configured to focus the reflected light into focused reflected light; and a photosensitive array, comprising: a first photosensitive element, configured to receive first focused reflected light of the focused reflected light; and a second photosensitive element, configured to receive second focused reflected light of the focused reflected light; and a processing unit, coupled to the photosensitive module and configured to perform time-of-flight (ToF) ranging based on ToF of the incident light and ToF of the reflected light to obtain a first distance corresponding to the target object, wherein the first distance has a global offset, wherein, the processing unit establishes an image on the basis of the first focused reflected light and the second focused reflected light, estimates a disparity reflected by the first focused reflected light and the second focused reflected light in the image, and calculates a global compensation coefficient on the basis of the disparity to compensate the global offset, characterized in that the photosensitive array further comprising: a phase detection pixel pair, comprising: a right-shielded phase detection pixel, comprising the first photosensitive element, wherein the right-shielded phase detection pixel is configured to shield light from the right side of the right-shielded phase detection pixel, and allow the first focused reflected light to enter the right-shielded phase detection pixel and to be received by the first photosensitive element; and a left-shielded phase detection pixel, comprising the second photosensitive element, wherein the left-shielded phase detection pixel is configured to shield light from the left side of the left-shielded phase detection pixel, and allow the second focused reflected light to enter the left-shielded phase detection pixel and to be received by the second photosensitive element. a light-emitting module, configured to emit incident light to a target object; and a photosensitive module, configured to receive reflected light of the incident light upon being reflected by the target object, wherein the photosensitive module comprises: a condenser lens, configured to focus the reflected light into focused reflected light; and a photosensitive array, comprising: a first photosensitive element, configured to receive first focused reflected light of the focused reflected light; and a second photosensitive element, configured to receive second focused reflected light of the focused reflected light; and a condenser lens, configured to focus the reflected light into focused reflected light; and a photosensitive array, comprising: a first photosensitive element, configured to receive first focused reflected light of the focused reflected light; and a second photosensitive element, configured to receive second focused reflected light of the focused reflected light; and a first photosensitive element, configured to receive first focused reflected light of the focused reflected light; and a second photosensitive element, configured to receive second focused reflected light of the focused reflected light; and a processing unit, coupled to the photosensitive module and configured to perform time-of-flight (ToF) ranging based on ToF of the incident light and ToF of the reflected light to obtain a first distance corresponding to the target object, wherein the first distance has a global offset, wherein, the processing unit establishes an image on the basis of the first focused reflected light and the second focused reflected light, estimates a disparity reflected by the first focused reflected light and the second focused reflected light in the image, and calculates a global compensation coefficient on the basis of the disparity to compensate the global offset, a right-shielded phase detection pixel, comprising the first photosensitive element, wherein the right-shielded phase detection pixel is configured to shield light from the right side of the right-shielded phase detection pixel, and allow the first focused reflected light to enter the right-shielded phase detection pixel and to be received by the first photosensitive element; and a left-shielded phase detection pixel, comprising the second photosensitive element, wherein the left-shielded phase detection pixel is configured to shield light from the left side of the left-shielded phase detection pixel, and allow the second focused reflected light to enter the left-shielded phase detection pixel and to be received by the second photosensitive element.