Replacement process of railway embedded iron seat

The invention discloses a replacement process of a railway embedded iron seat. The replacement process comprises the following steps: S1, primary drilling; a drill bit is used for punching to form a first hole; s2, secondary drilling is carried out; a drill bit is used for punching to form a second hole; s3, milling a counter bore; vertically milling by using a milling cutter from top to bottom to form a counter bore in the upper end surface; s4, filling a sealing element; a sealing ring is embedded in the counter bore; s5, high-pressure material injection; a high-pressure grouting machine is used for injecting thermal expansion aggregate into the first hole and the second hole along the counter bore, and the thermal expansion aggregate seeps out of a lower end pipe opening of the first hole and a lower end pipe opening of the second hole; s6, sealing; sealing a gap between the embedded iron seat and the embedded material by using a sealing filler; s7, heating is conducted; the pre-embedded iron base is heate