The present invention relates to a field of drug injection, and discloses a drug information detection device and a drug information detection type injection device. The drug information detection device is configured to detect an injected dose of an injection pen containing drug. The drug information detection device includes a housing, a rotary encoder configured to convert rotational information of the adjusting knob into drug injected dose information, and a control assembly. The rotary encoder includes an encoder body and a rotary block rotatably connected to the encoder body. The encoder body and the control assembly are electrically connected to each other. The housing is configured to cover the encoder body and the control assembly.
