During the determination of ferrophosphorus sample by X-ray fluorescence spectrometry (XRF) with fusion sample preparation, the key is to solve the problem of platinum-gold crucible corrosion in alloy sample pretreatment. The sample was firstly pre-oxidized at low temperature in ceramic ruthenium with graphite on the bottom and then mused at high temperature for sample preparation. A method for determination of phosphorus, silicon, manganese and titanium in ferrophosphorus by X-ray fluorescence spectrometry was established. The calibration samples of ferrophosphorus with certain content gradient were prepared using certified reference materials of ferrophosphorus according to a certain ratio as well as adding standard solution. The content range of calibration curves was broadened. Lithium carbonate and ruthenium peroxide composite oxidant were used to pre-oxidize the ferrophosphorus samples by slowly increasing the temperature from 400℃ to 800℃, avoiding the corrosion of platinum-gold crucible in sample melting process. The experimental results showed that the prepared glass pieces were uniform and stable under the following conditions: lithium tetraborate was selected as the flux; ammonium bromide solution was selected as the release agent; the dilution ratio was 40∶1; the melting temperature was 1100℃ and the melting time was 20min. The limits of detection for elements were between 32.47μg/g and 57.49μg/g. The standard sample of ferrophosphorus was determined under the optimal experimental conditions. The relative standard deviations (RSD, n=10) of determination results were between 0.28% and 1.1%. The proposed method was applied for the determination of actual ferrophosphorus samples, and the found results had no significant difference with those obtained by other methods.