I'll use a shielded CAT5 cable for RS485 line. The simplified bus structure is drawn in the picture . I have 130 slaves and their isolated part of RS485 IC is supplied from the supply placed at master. The cable length between slaves are about 0.5 meter. I tried it for 4 slaves and i'll increase it up to 130 slaves in the end. Is there any problem in this structure.
The only problem I can think of is that 130 LDOs with their input capacitors spread over 65m of relatively thin wire is an awful lot of a load on master supply.
Even though the individual power requirements of bus-side isolated part is probably small (you did not provide any references to actual components).
You may have to increase the supply voltage to something like 12V to get reliable power at the end of a chain, and you'll be wasting a lot of it on heat.
Other than that it should work.
With new information it looks OK. At 2 mA bus side and accounting for losses it could be somewhere around 0.5A load on power supply. Which is comparable to PoE.
The cable capacitance combined with 3000 uF should be manageable, although rather on high side. The datasheet for AP2204 recommends 1 uF input cap. I suggest you use that, maybe with additional 0.01 uF.