直剪试验全称直接剪切试验（Direct shear test），是土力工程中寻找土的抗剪强度的一种试验。

取土的试样放入剪切盒内，将上盒固定，下盒可沿水平方向滑动。首先施加垂直压力，然后在对剪切盒的下盒逐级施加水平剪力，直至试样被剪坏。一般要取4-5个试样，分别施加不同的垂直压力来重复试验。本试验由于简单易行，是测定土的抗剪强度的常用方法。

A direct shear test is a laboratory or field test used by geotechnical engineers to measure the shear strength properties of soil or rock material, or of discontinuities in soil or rock masses.

The U.S. and U.K. standards defining how the test should be performed are ASTM D 3080, AASHTO T236 and BS 1377-7:1990, respectively. For rock the test is generally restricted to rock with (very) low shear strength. The test is, however, standard practice to establish the shear strength properties of discontinuities in rock.