This paper proposes a single target detection method applied to narrow-band radar signals: a method based on sparse Radon transform. This method is suitable for low signal-to-noise ratio conditions. The target energy needs to be corrected to a range unit and then the direction modulation frequency is adjusted. On the basis of the original radar single target detection method, proper phase compensation is carried out and the target echo is made coherent. Finally, two detection methods applied to narrowband radar single target are proposed. The sparse Radon transform is used to verify the target detection. The method is effective, and on this basis, the accurate estimation of the target's motion parameters is achieved.