The invention relates to a transition metal doped cerium and titanium compound oxide catalyst for selective catalytic reduction of nitric oxide by ammonia, and a preparation method thereof. The catalyst in the invention is a transition metal (iron, tungsten and molybdenum) doped cerium and titanium compound oxide catalyst. The preparation method of the catalyst is a co-precipitation method, which comprises the following steps of: preparing mixed solution from cerium salt, titanium salt and salt corresponding to one or more transition metals of iron, tungsten and molybdenum, and continuously stirring for 3 to 15 hours at the temperature of between 50 and 150 DEG C by using one of ammonia water, sodium hydroxide, sodium carbonate, ammonium bicarbonate or urea; and filtering, washing, baking and calcining. In the invention, the adopted raw materials are non-toxic and harmless, the preparation method is simple and easy, the prepared catalyst has the characteristics of high catalytic activity, excellent N2 generation selectivity, broad operation temperature window, high space velocity reaction condition adaptability and the like, and is suitable for mobile sources represented by tail gas of diesel vehicles, as well as stationary source nitric oxide catalytic purification device represented by flue gas of coal fired power plants.