A silicon-based modulator, comprising: a first heavily doped contact region, a second heavily doped contact region, and a modulation arm working region comprising a first type doped region and a second type doped region, the first heavily doped contact region and the second heavily doped contact region being located at left and right sides of the modulation arm working region, respectively, the first heavily doped contact region being connected with the first type doped region, a PN junction being formed in a contact region between the first type doped region and the second type doped region, wherein an area of the contact region formed between the first type doped region and the second type doped region in the modulation arm working region is greater than an area of a smallest contact region between the first type doped region and the second type doped region; characterized in that: when the silicon-based modulator is looked down, there are a plurality of strip-shaped first type doped regions and a plurality of strip-shaped second type doped regions in the modulation arm working region; and the plurality of strip-shaped first type doped regions and the plurality of strip-shaped second type doped regions are distributed in an alternating continuous manner, and all the strip-shaped first type doped regions are connected and run through each other, and all the strip-shaped second type doped regions are connected and run through each other, and an intersection line of a first plane and PN junctions between the first type doped regions and the second type doped regions of the modulation arm working region presents as a rectangular wave-like broken line; wherein the first plane is a longitudinal section of the silicon-based modulator; or when the silicon-based modulator is looked down, the second type doped regions in the modulation arm working region are distributed in the first type doped regions in a dot matrix manner; and some intersection lines of a first plane and PN junctions between the first type doped regions and the second type doped regions of the modulation arm working region present as rectangular wave-like broken lines, and some intersection lines present as L-like broken lines, and the first type doped regions are connected in an integral run-through manner, and the second type doped regions are connected in an integral run-through manner; wherein the first plane is a longitudinal section of the silicon-based modulator, and the first plane corresponding to the intersection lines presented as the rectangular wave-like broken lines and the first plane corresponding to the intersection lines presented as the L-like broken lines are two different planes. when the silicon-based modulator is looked down, there are a plurality of strip-shaped first type doped regions and a plurality of strip-shaped second type doped regions in the modulation arm working region; and the plurality of strip-shaped first type doped regions and the plurality of strip-shaped second type doped regions are distributed in an alternating continuous manner, and all the strip-shaped first type doped regions are connected and run through each other, and all the strip-shaped second type doped regions are connected and run through each other, and an intersection line of a first plane and PN junctions between the first type doped regions and the second type doped regions of the modulation arm working region presents as a rectangular wave-like broken line; wherein the first plane is a longitudinal section of the silicon-based modulator; or when the silicon-based modulator is looked down, the second type doped regions in the modulation arm working region are distributed in the first type doped regions in a dot matrix manner; and some intersection lines of a first plane and PN junctions between the first type doped regions and the second type doped regions of the modulation arm working region present as rectangular wave-like broken lines, and some intersection lines present as L-like broken lines, and the first type doped regions are connected in an integral run-through manner, and the second type doped regions are connected in an integral run-through manner; wherein the first plane is a longitudinal section of the silicon-based modulator, and the first plane corresponding to the intersection lines presented as the rectangular wave-like broken lines and the first plane corresponding to the intersection lines presented as the L-like broken lines are two different planes.