This study delves into the dynamic operational states of nanowire sensors within microfluidic channels for flow velocity detection, classifying these states into decline, steady, and failure states. It conducts a comparative analysis of the steady-state operational characteristics of nanowire sensors across various voltages and inlet flow rates, alongside examining the interplay between nanowire resistivity and temperature. This investigation identifies an optimal working condition for the sensor at a 1 V operating voltage and a nanowire dimension of 150 × 150 nm. Employing both theoretical and experimental approaches, the research elucidates the convective heat transfer mechanism that underpins the functionality of the nanowire sensor for flow rate detection. It unveils the pattern of nanowire temperature changes during inlet flow rate measurement within a range from 10 to 50 μL/min range and establishes standard values of temperature and calorimetric differences for various flow velocities. Furthermore, the study achieves the prediction of the time to reach the steady and failure states under given operational conditions for the nanowire-based sensor. This advancement will enhance the reading precision of the signal output from the nanowire sensor, mitigate the risk of sensor failure, and contribute to prolonging the operational lifespan of equipment.