At the very least, you need a large enough dehumidifier and you need to plumb it to a little sump or into a drain. If all you have is fairly normal basement humidity then this may fix the situation entirely. If you rely on going down to empty the collection pan then it is probably sitting there, not running, while the pan is full for significant amounts of time.
You might have other issues, which we could only guess at. Think about these (below) and get back to us with any other questions:
What is the grading like around your house? If the ground slopes down toward your house then this might need to be addressed because rainwater on the ground could be flowing down hill then into, or around your basement. Fixes include changing the grade or providing drainage to divert runoff away from your basement.
What condition are your gutters and downspouts in? Very frequently, and I mean VERY, excess moisture is from overflowing gutters and/or improperly drained downspouts. Clean your gutters, make sure downspout runoff is diverted away from your house, go outside when it is raining hard and see what is going on. Are there puddles around any part of your house, near the foundation? If so, these may need to be addressed and eliminated.
There are other causes and many remedies for each condition so I'm sure others will have more to say