The utility model discloses a gardens flowers and trees soil PH detection circuitry, including battery, switch, first resistance to the 8th resistance, electric capacity, first triode to fourth triode, milliammeter and PH detector, in the PH detector inserted soil, when having signal output, first triode switched on, and the collector voltage of first triode descends, and the second triode ends, and the collector voltage of second triode rises, and the indicating circuit who comprises third triode, fourth triode and milliammeter switches on, and the milliammeter shows the pH value. Compared with the prior art, the utility model discloses an electronic components of minority constitute, low cost, and small in size adopts the milliammeter to show, and reading that can convenient and fast shows directly perceivedly, and convenient to use has the value of popularization and application.