A positioning system, comprising at least one projection device, at least one camera, and a positioning engine, wherein the positioning engine is connected to any of the at least one projection device, and the positioning engine is further connected to any of the at least one camera; the at least one projection device is configured to project a first optical pattern onto a target region, wherein the first optical pattern comprises a plurality of sub-regions; the at least one camera is configured to collect a second picture and send the second picture to the positioning engine, wherein the second picture comprises the first optical pattern and a to-be-positioned object located in the first optical pattern; and the positioning engine is configured to receive the second picture, and determine a location of the to-be-positioned object in the target region based on a location of the to-be-positioned object in the first optical pattern in the second picture; and the at least one camera is further configured to collect a first picture and send the first picture to the positioning engine, wherein the first picture comprises the first optical pattern projected by the at least one projection device onto the target region; and the positioning engine is further configured to receive the first picture and mark the target region based on the first picture; characterized in that the system comprises two projection devices: a first projection device and a second projection device, and that the positioning engine marks the target region based on the first picture by: receiving two first pictures, wherein the two first pictures are collected by the at least one camera and are a first picture comprising the first optical pattern projected by the first projection device onto the target region and a first picture comprising the first optical pattern projected by the second projection device onto the target region; identifying the plurality of sub-regions comprised in the first optical pattern from each of the two first pictures; and sending adjustment information to the first projection device and/or the second projection device, so that the first projection device and/or the second projection device make/makes adjustment based on the adjustment information, and sub-regions in the first optical patterns in the two first pictures are aligned, wherein the adjustment information is used to control alignment of the sub-regions in the first optical patterns in the two first pictures. the at least one projection device is configured to project a first optical pattern onto a target region, wherein the first optical pattern comprises a plurality of sub-regions; the at least one camera is configured to collect a second picture and send the second picture to the positioning engine, wherein the second picture comprises the first optical pattern and a to-be-positioned object located in the first optical pattern; and the positioning engine is configured to receive the second picture, and determine a location of the to-be-positioned object in the target region based on a location of the to-be-positioned object in the first optical pattern in the second picture; and the at least one camera is further configured to collect a first picture and send the first picture to the positioning engine, wherein the first picture comprises the first optical pattern projected by the at least one projection device onto the target region; and the positioning engine is further configured to receive the first picture and mark the target region based on the first picture; characterized in that the system comprises two projection devices: a first projection device and a second projection device, and that the positioning engine marks the target region based on the first picture by: receiving two first pictures, wherein the two first pictures are collected by the at least one camera and are a first picture comprising the first optical pattern projected by the first projection device onto the target region and a first picture comprising the first optical pattern projected by the second projection device onto the target region; identifying the plurality of sub-regions comprised in the first optical pattern from each of the two first pictures; and sending adjustment information to the first projection device and/or the second projection device, so that the first projection device and/or the second projection device make/makes adjustment based on the adjustment information, and sub-regions in the first optical patterns in the two first pictures are aligned, wherein the adjustment information is used to control alignment of the sub-regions in the first optical patterns in the two first pictures. receiving two first pictures, wherein the two first pictures are collected by the at least one camera and are a first picture comprising the first optical pattern projected by the first projection device onto the target region and a first picture comprising the first optical pattern projected by the second projection device onto the target region; identifying the plurality of sub-regions comprised in the first optical pattern from each of the two first pictures; and sending adjustment information to the first projection device and/or the second projection device, so that the first projection device and/or the second projection device make/makes adjustment based on the adjustment information, and sub-regions in the first optical patterns in the two first pictures are aligned, wherein the adjustment information is used to control alignment of the sub-regions in the first optical patterns in the two first pictures.