Is there any option/settings to change before importing csv file in Process simulate for weld point location accuracy. Because after importing weld poinits into PS. There is variation of (x,y and z) dimensions which is in csv file and in PS.
There is not such option. Values should be exact as defined in csv.
What kind of variation?
Only coordinates, or wrong orientation?
Maybe due to the fact that your part and working-frame are not aligned? Then you must "set working frame" to your part's self-origin, before importing the csv. Also "use working-frame" must be checked.
When importing a csv file you need to take care of the unit you're using, they are not "fully connected" to the unit set on the software.
For example, in csv files that I import for my MFGs, the rotation values in the csv file are in radians, although the unit set on the software for angle is degrees. During this process, the fields will be automatically converted to degrees, but in the csv file is mandatory to be in radians.
I believe same idea is applied to linear units. In csv files (and also in PS) I use milimeters without any problems. Are you using this linear unit for your xyz values in the csv file?