Abstract: Shear capacity is one of the basic mechanical properties of wood, and is also an important parameter in the design of wood structures. There is a certain difference between the shear strength of wood obtained by the compression-shear test using the national standard test method and the pure shear test, and there may be stress concentration at the end of the V-notch opening in the commonly used Iosipescu shear test. Therefore, this study investigates the distribution of shear stress on the shear surface of V-notch and of Keyhole-shaped specimens using a finite element model, and selects the specimens with the optimal opening form to conduct mechanical tests. The research shows that when the V-notch opening is 0°~90°, the stress concentration phenomenon at both ends of the shear plane is gradually weakened and the shear stress distribution gradually become uniform with the increase of the opening angle. The shear stress distribution of Keyhole-shaped specimens is independent of the opening angle and form, but is related to the arc size, and the smaller the arc size, the smaller the shear stress variation coefficient. Comprehensively considering the processing difficulty, stress concentration, failure location, stress distribution, and central stress, the 90° V-notch specimen is relatively suitable, followed by the 3 mm arc radius Keyhole-shaped specimen. The shear failure modes, stress-displacement curves, and stress-strain curves of these two specimens are similar, but there are still some differences in shear modulus and shear strength.