A full-open-cavity wavelength-tunable random fiber laser[WT-RFL]with compact structure and hundreds of picometers tuning range is proposed and demonstrated.A π fiber Bragg grating[FBG]is used in the WT-RFL as a filter to select lasing wavelengths.The two random Bragg grating arrays[RBGAs]and a section of high gain erbium-doped fiber result in a low lasing threshold and high stability.A numerical model to analyze the tunable characteristics is developed.The results show that the laser threshold is 22 mW,and the maximum peak-power fluctuation is 0.55 dB.To the best of our knowledge,it is the first time that a compact and full-open-cavity WT-RFL with two RBGAs and a π-FBG is proposed.