The invention discloses a method for analysis and on-line monitoring of the vibration performance of band steel in a continuous annealing unit furnace, belonging to the technical filed of annealing. The invention comprises the following processing steps: collecting technological parameters of key equipment of a continuous annealing unit; collecting the width, thickness, type of steel and signal sampling period of the continuous unit in annealing process; selecting the time period required by the analysis of vibration performance of the band steel in the furnace; utilizing ibaAnalyzer software to open a PDA database; exporting actual values of tension at each time in the sub-processes, such as preheating, heating, soaking, slow cooling, splat cooling, aging, finally cooling and the like in the time period; calling a vibration performance analysis module to output the vibration frequency and vibration power of each sub-process; presetting a critical power allowance value of vibration performance; and comparing the value of the maximal power of each sub-process with that of the critical power, and monitoring whether harmful vibration exists to finish analysis and on-line monitoring on the vibration performance of the band steel in the continuous annealing unit furnace. The invention has the advantage of being capable of timely and quantitatively analyzing main frequency, energy and other vibration performance parameters of the band steel inside a furnace, realizing on-line monitoring and taking economic benefit for enterprises.