The high reliability LC filters with ceramic substrate integrated package were fabricated by using the reflow soldering method. The resistance spot welding process was used to fix the pins of the winding inductor, and the chip capacitors were fixed by SMT red adhesive, thus the pre-fixation of the internal components in the ceramic substrate integrated packaging LC filter was achieved. The solder paste was added by coating and the well wetted welding spots were formed, the residual flux was removed and cleaned by using the micro-pressurized water column. After debugging and glueing to fix the wound inductor, the parallel seam welding is used implement the product packaging. The process inspection, temperature and mechanical test of the LC filter fabricated by reflow soldering assembly were carried out. The results show that the LC filter fabricated by proposed assembly process have good process through rate, meet the requirements of high reliability environmental applications, and are suitable for mass production.