Because of the difference of handedness and some special habits or training methods, everyone's muscles will have some left-right asymmetry, which is a normal phenomenon, such as some people's left-right chest asymmetry and arm asymmetry. However, as you train, this difference will get smaller and smaller, because the muscle circumference can't grow endlessly.

How to better cultivate the integrity of the back

Of course, if you want to change this situation, you can try to do some training mainly on the weak side, or more directly, you can do unilateral training directly with one hand, such as dumbbell stroke, mechanical stroke, one-handed D handle pull-down, one-handed T handle stroke and so on. Give priority to the weak side and multiply it several times, and the difference will be improved gradually, so don't worry too much about minor problems.