The invention discloses a quasi-distributed stratum temperature fine measuring system which comprises a serial sensing acquisition portion in a measuring area and a serial temperature sensing portion imbedded in a stratum measurement well, wherein the serial sensing acquisition portion comprises first and second sets of multipath change-over switches, a pulse generator, a single-chip microcomputer and an interface chip, the first set of multipath change-over switches comprise a first multipath change-over switch and a second multipath change-over switch, the second set of multipath change-over switches comprise a third multipath change-over switch and a fourth multipath change-over switch, and the serial temperature sensing portion comprises a part of category 5e twisted-pair cables and a plurality of platinum thermal resistors. Orange, brown, green and blue leads of category 5e twisted-pair cables and orange-white, brown-white, green-white and blue-white leads form a 4*4 matrix, A platinum thermal resistor is connected to each node of the matrix, and the rest part of the category 5e twisted-pair cables is connected the first and second sets of multipath change-over switches. The sensing data of the system can be transmitted reliably in a long distance, thereby ensuring long-term stable working. The cost performance is high, and the quasi-distributed stratum temperature fine measuring system can be widely promoted.