Three kinds of glass sharp electrospray ionization devices were built for direct mass spectrometry (MS) analysis using sharp slide,slender capillary and sharp dropper. Through the simulation experiment and mass spectrometry experimental investigation,the influence of the experimental conditions was studied. Under the optimum working conditions such as the electrospray tip diameter was less than 0.24 mm, the distance between the electrospray tip and the MS sample inlet was 10 mm, the electrospray voltage was 4.5 kV, the electrospray capillary angle was about 5.0°-7.5° (upper at back) and the left and right angles were 0°, 0.1 mg/mL sample solution(containing 1% formic acid for positive ion detection,or ammonium hydroxide for negative ion detection) could be well analyzed by MS. In positive or negative ion modes, the quinine, mandelic acid,benzoin,phenylalanine and other different types of sample solutions were analyzed by MS. The result showed that quinine,mandelic acid,benzoin,phenylalanine,tartaric acid,2,5-dihydroxybenzoic acid (DHB) and tangeretin could be detected in positive ion mode using sharp dropper electrospray. DHB, phenylalanine, tartaric acid and mandelic acid were detected in negative ion mode. Sharp slide electrospray was suitable for measuring the stable sample in the air, capillary electrospray and sharp dropper electrospray were suitable for detecting many low viscosity sample solution even instable sample. Using the method, the extraction solution of propranolol hydrochloride tablet and berberine hydrochloride tablet was directly analyzed by MS. The results showed that the glass sharp electrospray method had the advantages such as without carrier gas, simple structure, easy to build and operate, rapid analysis, anti-cross pollution, and could be conveniently used for MS analysis.