To investigate the driving mechanisms of orbital evolution across different mass ratios and evolutionary stages, we present the first multi-color photometric solutions and detailed orbital period analyses for four short-period eclipsing binaries: MX Ser, AY Pup, QW And, and TZ CrA. By analyzing the light curves using the Wilson–Devinney code, we determined the absolute parameters and geometric configurations for these systems. MX Ser (q = 4.60) and AY Pup (q = 2.02) have been identified as W-subtype contact binaries with medium fill-out factors of f ∼ 30%. QW And (q = 0.51) is derived as an A-subtype contact binary (f ≈ 32%) exhibiting significant magnetic activity modeled by a cool starspot. In contrast, TZ CrA (q = 0.31) is confirmed to be a semi-detached Algol-type system with a large temperature difference (ΔT ≈ 2175 K), where the secondary component fills its Roche lobe while the primary remains detached. The orbital period analyses based on all available minimum times reveal that all four systems are undergoing continuous secular period decreases. We attribute these variations to different physical mechanisms governed by the mass ratio (q). For the high mass-ratio systems MX Ser and AY Pup (q > 1), the period decrease is dominated by conservative mass transfer from the massive secondary to the primary, consistent with the thermal relaxation oscillation (TRO) theory. For the low mass-ratio systems QW And and TZ CrA (q < 1), the period decrease is the net result of competing mechanisms, where angular momentum loss (AML) via magnetic braking completely overwhelms the mass transfer effect. The derived evolutionary status suggests that while MX Ser, AY Pup, and QW And are evolved contact binaries, TZ CrA represents a critical “pre-contact” stage (short-period Algol). Driven by efficient AML, the detached primary of TZ CrA is expected to eventually fill its Roche lobe, evolving the system into an A-subtype W UMa contact binary.