The invention relates to the field of material synthesis, in particular to 3-(2-chloro-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one and synthesis and application thereof, aiming to solve the problem of restricted development of meropenem due to complicated existing methods for synthesizing 3-(2-Bromo-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one, strict reaction conditions and low yield. A method for preparing the 3-(2-chloro-1-oxopropyl)-spiro[2H-1,3-benzoxazine-2,1'-cyclohexan]-4(3H)-one includes steps of 1, placing intermediates I, pyridine, chloropropionyl chloride and reactive solvents into a reactor according to a molar ratio of 1:(1-3):(1-3):(5-10), carrying out reaction at the temperature of 30-50 DEG C under the control for 3-5 h, concentrating the solvents and cooling and crystallizing reaction products to obtain F-6; 2, adding mixed liquid of organic solvents and salt solution into the F-6 obtained in the step 1, completely dissolving the F-6, stirring the F-6 and the mixed liquid, allowing the F-6 and the mixed liquid to stand still and then layer, cooling separated organic phases obtained by means of layering, precipitating out solid, carrying out suction filtration on the solid and drying the solid to obtain refined products. Raw materials for synthesizing the F-6 are easily available, the method includes few reaction steps, reaction conditions are mild, only few byproducts are generated, the method is easy and convenient to implement, and the used solvents can be recycled.