The constitution of the Confederate States of America was very similar to the United States of America Constitution. And why shouldn't it be? After all, a Southerner, Thomas Jefferson, wrote the US Constitution and it was adopted by their forefathers. This was the main reason the states of the South declared their independence and seceded to form their own government. The northern states and the Federal government had strayed from the constitution adopted by their forefathers.
Most of the Bill of Rights in the United States Constitution was incorporated into the Confederate Constitution.
There are other small adjustments and tweaks throughout the document to correct things Southerners felt were in error with the original document and to balance power between the states and the federal government.