Liquid concentration detection systems have been widely used in food, chemical, pharmaceutical, and many other industries. When the liquid flows, a large number of vortices will usually be generated, resulting in increased turbulence intensity, which will interfere with the detection of the concentration of the suspension. In this paper, a method for concentration detection by differential pressure based on turbulence elimination is proposed to improve the reliability of concentration detection results. The changes in the internal flow field corresponding to different lengths of the turbulence elimination structure and different inlet angles are analyzed through numerical simulation. Finally, the influence of changes in structure parameters on the accuracy of concentration detection is tested through experiments. The results show that when the length of the turbulence elimination structure is small, the vortex zone inside the concentration detection device changes with the inlet velocity. When the length of the turbulence elimination structure is 150 mm, the vortex zone is basically not affected by the inlet velocity. The stability of the flow field increases with the increase in the inlet angle. When the inlet angle increases to 60°, a stable zone of turbulence will form in the region where Y > 0.4 m. When the length of the turbulence elimination structure is 150 mm and the inlet angle is 60°, the expected experimental results are obtained, and the actual needs of liquid concentration measurement are met.