Handheld shading oximeter

The handheld shading oximeter comprises a handle and a detection head arranged on the handle, a display screen and an optical signal detection terminal are arranged on the detection head, a detection circuit board is arranged in the detection head, an optical signal emitting element and an optical signal detection element are arranged at the end of the optical signal detection terminal, and the optical signal emitting element is used for emitting light to a detection part. The detection circuit board is used for determining the blood oxygen saturation degree of the tissue according to the emitted and received light signals, and the display screen is used for displaying a measurement result; the oximeter further comprises a shading assembly which comprises a connecting cylinder and a shading cover. An outer sleeve is arranged around the optical signal detection terminal; the light shield is made of a soft light shielding material; one end of the connecting cylinder is hermetically and fixedly connected with th