A three-dimensional image sensor, configured to receive light (LT_P1, LT_P2, LT_P3, LT_P4) emitted from a light-emitting module and reflected from a target object to generate a first depth information and a second depth information for a first location and a second location of the target object, respectively, wherein the 3D image sensor comprises: a photosensitive pixel array, comprises: a first photosensitive pixel; a second photosensitive pixel; and a pixel control signal transmission line, having a first node and a second node respectively coupled to the first photosensitive pixel and the second photosensitive pixel to transmit a pixel control signal to the first photosensitive pixel and the second photosensitive pixel, so that the first photosensitive pixel and the second photosensitive pixel respectively output a first photosensitive value (Q1_TX1_d1) and a second photosensitive value (Q1_TX1_d2) corresponding to the first location and the second location of the target object according to the pixel control signal; wherein a length of a transmission line between the first node and the first photosensitive pixel equals a length of a transmission line between the second node and the second photosensitive pixel, so that time taken for the pixel control signal to reach the first photosensitive pixel from the first node is the same as time taken for the pixel control signal to reach the second photosensitive pixel from the second node, and the pixel control signal reaches the first node at a first time point and reaches the second node at a second time point, wherein the second time point is later than the first time point; a delay detection module (400, 700, 800), wherein the delay detection module (400, 700, 800) comprises: a first delay detection circuit (402, 702), having a first input terminal (in1, in11) and a second input terminal (in2, in12) respectively coupled to the first node and the second node and configured to determine a time difference (t2-t1) between the first time point and the second time point; and a processing unit, configured to generate the first depth information and the second depth information based on the first photosensitive value (Q1_TX1_d1), the second photosensitive value (Q1_TX1_d2), and the time difference (t2-t1). a photosensitive pixel array, comprises: a first photosensitive pixel; a second photosensitive pixel; and a pixel control signal transmission line, having a first node and a second node respectively coupled to the first photosensitive pixel and the second photosensitive pixel to transmit a pixel control signal to the first photosensitive pixel and the second photosensitive pixel, so that the first photosensitive pixel and the second photosensitive pixel respectively output a first photosensitive value (Q1_TX1_d1) and a second photosensitive value (Q1_TX1_d2) corresponding to the first location and the second location of the target object according to the pixel control signal; wherein a length of a transmission line between the first node and the first photosensitive pixel equals a length of a transmission line between the second node and the second photosensitive pixel, so that time taken for the pixel control signal to reach the first photosensitive pixel from the first node is the same as time taken for the pixel control signal to reach the second photosensitive pixel from the second node, and the pixel control signal reaches the first node at a first time point and reaches the second node at a second time point, wherein the second time point is later than the first time point; a first photosensitive pixel; a second photosensitive pixel; and a pixel control signal transmission line, having a first node and a second node respectively coupled to the first photosensitive pixel and the second photosensitive pixel to transmit a pixel control signal to the first photosensitive pixel and the second photosensitive pixel, so that the first photosensitive pixel and the second photosensitive pixel respectively output a first photosensitive value (Q1_TX1_d1) and a second photosensitive value (Q1_TX1_d2) corresponding to the first location and the second location of the target object according to the pixel control signal; wherein a length of a transmission line between the first node and the first photosensitive pixel equals a length of a transmission line between the second node and the second photosensitive pixel, so that time taken for the pixel control signal to reach the first photosensitive pixel from the first node is the same as time taken for the pixel control signal to reach the second photosensitive pixel from the second node, and the pixel control signal reaches the first node at a first time point and reaches the second node at a second time point, wherein the second time point is later than the first time point; a delay detection module (400, 700, 800), wherein the delay detection module (400, 700, 800) comprises: a first delay detection circuit (402, 702), having a first input terminal (in1, in11) and a second input terminal (in2, in12) respectively coupled to the first node and the second node and configured to determine a time difference (t2-t1) between the first time point and the second time point; and a processing unit, configured to generate the first depth information and the second depth information based on the first photosensitive value (Q1_TX1_d1), the second photosensitive value (Q1_TX1_d2), and the time difference (t2-t1).