The content of lithium in lithium-boron alloy plays a decisive role in the electrochemical performance of batteries. When lithium is determined by gravimetry, the process is long and the determination is interfered by a large number of coexisting boron. The determination method of lithium content in lithium-boron alloy by lithium sulfate gravimetry after removing boron with methanol was investigated in experiments. The sample was dissolved by dilute nitric acid. Then 2.0mL of anhydrous methanol was added. The solution was heated in thermostatic water bath at 90℃ to remove boron via volatilization. Then 2.0mL of sulfuric acid (1+1) and a small amount of water were added to dissolve the salts. The solution was transferred into platinum crucible and heated at high temperature until the sulfuric acid smoke was exhausted. The platinum crucible was transferred into muffle furnace at 800℃ and heated for 3h. Lithium was converted to lithium sulfate. After constant weight, the contents of boron oxide and magnesium sulfate in solid were determined by inductively coupled plasma atomic emission spectrometry to modify the determination results. The proposed method was applied for the determination of lithium content in three actual lithium-boron alloy samples. The relative standard deviations (RSD, n=11) of determination results were between 0.34% and 0.56%. The spiked recoveries were between 98% and 103%.