Abstract: Based on the theories of fluid and rock mechanics, we have studied the variation of porosity and permeability coefficients of the wells Su02, Su03, Su06, Su18 and Dingyuan04 with barometric pressure and tidal effect in aquifer medium under undrained condition. Using the micro dynamic models of well-aquifer system under the conditions of force and water balance, we also analyzed the mechanism of simultaneous rise in water level since the second half of 2014. The results show that: ① There is a linear relationship between the barometric coefficient and the tidal factor of M₂ wave for the five wells, that is, the lager the barometric coefficient, the larger the tide factor; ② A set of synchronous enlargement phenomenon occurred in porosity and permeability coefficient of each well, which is mainly because that the recharge is greater than the discharge.