To realize a propeller-driven Mars airplane, the propeller-wing flow interaction characteristics should be clarified. Thus, we conducted numerical simulations of the propeller-wing interaction at low Reynolds number conditions (Re = 3.0 × 10⁴) corresponding to Mars atmosphere, focusing on the propeller slipstream effects on the fixed wing. Solutions for the tractor case (propeller in front of the fixed wing) and the wing only case were compared. The results showed that in the tractor case, the lift coefficient (C_L) of the fixed wing increased with the angle of attack (α) more linearly than for the wing only case and showed delayed stall because the propeller slipstream favorably suppressed the expansion of the recirculation region over the fixed wing in the time-averaged flow fields, supporting the experimental result. The flow over the fixed wing separated from near the leading-edge in both low and high thrust conditions even at a moderate angle of attack (α = 5°), whereas previous studies at relatively high Reynolds numbers (Re ∼ O(10⁵)) showed that almost attached flow fields were formed under the propeller slipstream influence. Additionally, it was observed that the C_L fluctuation of the fixed wing increased even when the time-averaged C_L was lower than that of the wing only case.