A virtual reality, VR, system comprising two optical base stations (100, 300), a head-mounted display device adapted to be worn by a user, and at least one control handle adapted to be held by a user, wherein each optical base station (100, 300) comprises: a base; a light source, disposed on the base for providing a light beam; a rotation plate, disposed on the base; and an optical fiber (140, 340), disposed on the base and having an input end (142, 342) and a first output end (144A, 344A), wherein the rotation plate is adapted to drive the optical fiber (140, 340) to rotate around a rotation axis, the rotation axis passes through the input end (142, 342), and the light beam entering the optical fiber (140, 340) from the input end (142, 342) is transmitted in the optical fiber (140, 340) and output from the first output end (144A, 344A); a cover, disposed on the base, wherein the light source, the rotation plate and the optical fiber (140, 340) are located in an accommodation space formed by the cover and the base, and the cover is transparent to the light beam; wherein an inner top surface of the cover which is remote from the base has at least one reflecting portion, and the light beam enters the input end (142, 342) after being reflected by the reflecting portion. wherein the light beam output from the first output end (144A, 344A) scans the periphery of the base at 360 degrees without dead space; wherein the optical base stations (100, 300) are configured to continuously and periodically emit light beams to a space where the user is located; wherein a plurality of light sensors are disposed on the head-mounted display device and the control handle, wherein the light sensors are capable of detecting the light beams emitted from the optical base stations (100, 300); wherein by analyzing time information related to the light beams detected by the light sensors and geometric positions of the light sensors on the head-mounted display device and the control handle, instant position information regarding the head-mounted display device and the control handle in the space is obtainable; and wherein each optical base station (100, 300) further comprises a first lens module (170, 170A, 170B) disposed at the first output end (144A, 344A), wherein the light beam, after being output from the first output end (144A, 344A), passes through the first lens module (170, 170A, 170B) and is converted to have a linear spot. a base; a light source, disposed on the base for providing a light beam; a rotation plate, disposed on the base; and an optical fiber (140, 340), disposed on the base and having an input end (142, 342) and a first output end (144A, 344A), wherein the rotation plate is adapted to drive the optical fiber (140, 340) to rotate around a rotation axis, the rotation axis passes through the input end (142, 342), and the light beam entering the optical fiber (140, 340) from the input end (142, 342) is transmitted in the optical fiber (140, 340) and output from the first output end (144A, 344A); a cover, disposed on the base, wherein the light source, the rotation plate and the optical fiber (140, 340) are located in an accommodation space formed by the cover and the base, and the cover is transparent to the light beam; wherein an inner top surface of the cover which is remote from the base has at least one reflecting portion, and the light beam enters the input end (142, 342) after being reflected by the reflecting portion. wherein the light beam output from the first output end (144A, 344A) scans the periphery of the base at 360 degrees without dead space; wherein the optical base stations (100, 300) are configured to continuously and periodically emit light beams to a space where the user is located; wherein a plurality of light sensors are disposed on the head-mounted display device and the control handle, wherein the light sensors are capable of detecting the light beams emitted from the optical base stations (100, 300); wherein by analyzing time information related to the light beams detected by the light sensors and geometric positions of the light sensors on the head-mounted display device and the control handle, instant position information regarding the head-mounted display device and the control handle in the space is obtainable; and wherein each optical base station (100, 300) further comprises a first lens module (170, 170A, 170B) disposed at the first output end (144A, 344A), wherein the light beam, after being output from the first output end (144A, 344A), passes through the first lens module (170, 170A, 170B) and is converted to have a linear spot.