Coconut coir is a cultivation substrate that is gradually gaining widespread application;however, the dynamic changes of its internal water content under drip irrigation across temporal and spatial dimensions, especially at a fine scale, remain insufficiently studied. To address this issue, a sensor array to monitor long-term water content variations within coconut coir was employed. The water movement rate, morphology of wetted body, and spatiotemporal distribution characteristics of the wetted body’s water content were investigated. Experimental results indicated that during drip irrigation, the vertical movement rate of the wetting front significantly exceeded the horizontal movement rate. The movement distance and vertical movement rate of the wetting front exhibited a power function relationship with infiltration time. The water content within the wetted body was increased in an S-shaped curve over time, reaching a relatively stable state after 20 hours of irrigation. As infiltration time increased, the shape of the wetted body transformed from an inverted cone to a barrel shape. Post-irrigation, the internal water content of the wetted body changed in two stages：a rapid short-term decline following a power function relationship, and a medium- to long-term decline following an exponential decay function, with the wetted body gradually shrinking in a conical form.