A nozzle arc temperature non-contact measurement system based on optical fiber transmission comprises an optical acquisition and processing system, a photoelectric converting system and a data processing unit. According to the nozzle arc temperature non-contact measurement system based on the optical fiber transmission, the optical fiber sensing technology is combined with optical signal processing device modulation and detection of optical wave characteristic parameters in the optical fiber transmission to achieve dynamic measurement on temperature physical quantity, and the system has the advantages of being good in beam quality, strong in anti-interference capacity, compact and compositive in structure, high in measurement precision, free of disturbance on arc fields, safe, reliable, fast in dynamic response speed and the like, and the problem that optical signals in a nozzle are difficult to sample is solved. Real-time control over dynamic saturation of optical signals and adjustment of dynamic gain balance can be achieved by using a variable optical attenuator. Monochromatic light beams of different characteristic wavelengths are separated through a wavelength division multiplexer, and an integration level is high. An infrared radiation thermometry and a visible spectrum thermometry are combined, the arc temperature is obtained by adopting a digital processing unit through operation of a relative spectral line intensity method, a dynamic measurement range is enlarged, and the dynamic response speed of measurement is improved.