The invention discloses a sealing test instrument and method. The test instrument comprises an instrument body, and the instrument body is provided with a first sensor and a second sensor isolated from the first sensor; a first pressure transmitting channel communicated with an upper oil pipe channel is formed in the instrument body, the upper oil pipe channel and a lower water injection channel of a water distribution cylinder are communicated with a lower oil pipe channel, and the first sensor is arranged in the first pressure transmitting channel to measure the pressure thereof; a second pressure transmitting channel communicated with an upper water injection channel of the water distribution cylinder is formed in the instrument body, and the second sensor is arranged in the second pressure transmitting channel to measure the pressure thereof; and first and second sealing parts are formed on the instrument body, the upper oil pipe channel is separated from the upper water injectionchannel by the first sealing part, and the upper water injection channel is separated from the lower water injection channel by the second sealing part. Thus, sealing of a bushing protective packer and a layered injection packer of an integrated concentric water injection tube can be tested.