The invention discloses a two-dimensional flexible shear stress sensor and a measuring method thereof, and belongs to the technical field of electronic devices. The two-dimensional flexible shear stress sensor comprises an X hot line and a Y hot line which are made of a heat-sensitive material Ni. The X hot line is composed of a first X sub hot line and a second X sub hot line. The Y hot line is composed of a first Y sub hot line and a second Y sub hot line. The two ends of the first X sub hot line, the second X sub hot line, the first Y sub hot line and the second Y sub hot line are respectively coupled to drive electrodes made of copper. External electrodes made of copper are arranged on an underlying substrate. Each drive electrode is connected with the corresponding external electrode through a copper wire. A surface substrate fully covers the X hot line, the Y hot line and the drive electrodes, and the surface substrate does not cover the external electrodes. According to the invention, the fluid change resolution in the boundary layer of a flow field is improved, the two-dimensional shear stress in the boundary layer of fluid under the condition of high Reynolds number can be measured accurately, and sensor arraying is facilitated.