In this work, the absorption performance, regeneration performance, and cyclic absorption capacity of three kinds of mixed monoethanolamine (MEA) solvents were studied compared to those of using MEA solvents alone in self-made apparatuses, including MEA-piperazine (PZ), MEA-potassium carbonate (K2CO3), and MEA-ammonia (NH3). The mixed solvent of 10 wt% MEA/5 wt% PZ has a similar absorption performance and a higher regeneration temperature compared with the 20 wt% MEA solvent. And the mixed solvent of 10 wt% MEA/5 wt% K2CO3 has the lowest initial absorption rate, but it has a better cyclic absorption performance and a longer effective reaction time. The mixed solvent of 10 wt% MEA/5 wt% NH3 has both a faster absorption rate and a lower regeneration temperature. These results prove that the mixed MEA solvent mixed with K2CO3 or NH3 has good potential to replace the MEA solvent alone with a lower energy consumption.