Disclosed are crystalline free bases of 9-((8-fluoro-6-(1-methyl-1H-pyrazol-4-yl)-[1,2,4]triazolo[4,3-a]pyridine-3-yl)thio)-4-methyl-2H-[1,4]oxaazido[3,2-c]quinoline-3(4H)-one as a C-Met inhibitor or crystalline acid salts thereof, and preparation methods and uses thereof.In particular, disclosed are crystal forms I, II, III and IV of the free bases; crystal form I of the hydrochloride; crystal forms I and II of the sulfate; crystal forms I, II, III and IV of the phosphate; crystal forms I, II, III, IV and V of the mesylate; crystal forms I, II and III of the p-toluenesulfonate; crystal forms I, II and III of the 1,5-naphthalenedisulfonate; and the methods for preparing the above-mentioned crystal forms and a pharmaceutical composition comprising same, and a pharmaceutical use thereof and a method for regulating the catalytic activity of a protein kinase.