The invention provides a high-performance lithium iron phosphate cathode material for a lithium ion battery. During the preparation process, a carbon source used is a product obtained after nitrogen treatment of cigarette filters in ammonia gas. The invention also provides a preparation method of the lithium iron phosphate cathode material. The preparation method comprises the following steps: a product obtained after nitrogen treatment of cigarette filters in ammonia gas is firstly used as a carbon source of the lithium iron phosphate cathode material; then, an iron source, a lithium source, a phosphorus source and the above carbon source successively undergo uniform mixing, ball milling, drying, crushing and roasting so as to prepare the lithium iron phosphate cathode material. The lithium iron phosphate cathode material has outstanding merits as follows: the preparation technology is simple; cost is low; and the material is easy for large-scale production. As the product obtained after nitrogen treatment of waste cigarette filters in ammonia gas is used as the carbon source, resources are saved to realize cyclic utilization of wastes, and the lithium iron phosphate cathode material with high specific capacity and good rate capability also can be obtained. The lithium iron phosphate cathode material has important practical application value.