The numerical simulation of the basic equations of two-dimensional fluid mechanics is carried out to investigate the convective characteristics of the rectangular cavity in a certain inclination angle under uniform heating at the Prandtl number Pr=6.99, and the influence of different control parameters on the convection pattern and the velocity profile is also discussed. The following two conditions are mainly calculated: one is controlling relative Rayleigh number and changing the inclination angle of cavity; the other is controlling cavity tilt angle and changing relative Rayleigh number. The results showed that when the inclination angle is constant and small, the number of rolls and the absolute value of velocity increases gradually with the increase of relative Rayleigh number, and when the relative Rayleigh number is constant, the number of rolls and the absolute value of flow velocity decreases with the increase of inclination angle.