With the continuous development of science and technology, medical diagnosis technology also makes continuous progress. Ultrasound technology, as a means of medical diagnosis, has been widely used in various medical fields. It has been widely recognized by doctors and patients because it is harmless to the human body and can dynamically and clearly show the health state of human tissues and organs. With the continuous development of ultrasound technology, people have higher requirements for the quality of ultrasound imaging. Due to the limitations of the materials of ultrasonic probes, such as for the manufacturing of ceramic transducer, and the compromise scheme of low-channel scanning adopted to reduce the cost and frame rate, the caused noises and artifacts will block the useful information of human tissues and organs, which will seriously affect doctors’ auxiliary diagnosis. In the field of ultrasound, how to enhance images and videos and suppress artifacts has become an important challenge. This study describes several filtering algorithms for artifact suppression in the spatial domain and their limitations and proposes an artifact suppression algorithm based on the frequency domain, which can well suppress the periodic artifact in real-time ultrasonic imaging. Firstly, this study simulates the periodic artifact with a sine wave to highlight its characteristics in the frequency domain. Then, the ultrasonic image is subjected to a two-dimensional Fourier transform into the frequency domain to suppress these artifacts. Because these artifacts are periodic, they have obvious characteristics in the frequency domain. The set corresponding to these artifacts in the frequency domain is found through the algorithm model of sliding window scanning combined with a threshold. Next, according to the dynamic range of the frequency domain and the given threshold, the points of these suspected artifacts in the set are depressed. Finally, the ultrasonic image is transformed into the spatial domain by inverse Fourier transform to obtain the processed image. This method can improve the suppression of periodic artifacts in ultrasonic images and retain useful information, thus able to enhance the accuracy of doctors’ judgment regarding human organ conditions.