宋政(zheng)和三(san)年(nian)(1113年(nian)),太平寺(si)僧(seng)人(ren)(ren)惠鄙(bi)、守(shou)恩等(deng)(deng)倡議造(zao)橋(qiao)(qiao)(qiao),后鄉人(ren)(ren)林(lin)遷、林(lin)霸(ba)、陳侈、僧(seng)人(ren)(ren)妙覺(jue)等(deng)(deng)繼(ji)續募緣(yuan)建(jian)造(zao),于(yu)宋宣和六(liu)年(nian)(1124年(nian))建(jian)成(cheng)(cheng)。初名(ming)螺(luo)江(jiang)橋(qiao)(qiao)(qiao)。南(nan)宋紹(shao)興(xing)三(san)十年(nian)(1160年(nian)),少(shao)卿林(lin)栗根(gen)據“江(jiang)南(nan)沙合接龍(long)(long)(long)首”的古讖語,更名(ming)為(wei)“龍(long)(long)(long)江(jiang)橋(qiao)(qiao)(qiao)”。 龍(long)(long)(long)江(jiang)橋(qiao)(qiao)(qiao)是座(zuo)梁(liang)(liang)式結構的石(shi)(shi)橋(qiao)(qiao)(qiao),上至石(shi)(shi)欄和獨(du)具匠心的橫鋪石(shi)(shi)板,下至填(tian)基架梁(liang)(liang),均以石(shi)(shi)為(wei)材(cai)。現龍(long)(long)(long)江(jiang)橋(qiao)(qiao)(qiao)有(you)40孔,孔徑9~13米,橋(qiao)(qiao)(qiao)寬(kuan)4.2~5.2米,全(quan)長476米。橋(qiao)(qiao)(qiao)墩(dun)(dun)高6米,成(cheng)(cheng)舟形,兩分(fen)水尖(jian)間長為(wei)10米,墩(dun)(dun)寬(kuan)3.3~4.2米。6條石(shi)(shi)梁(liang)(liang)并排鋪設在墩(dun)(dun)頂帽石(shi)(shi)上。石(shi)(shi)梁(liang)(liang)寬(kuan)60~75厘米,厚60~90厘米,每條石(shi)(shi)梁(liang)(liang)約(yue)重15噸(dun)。在石(shi)(shi)梁(liang)(liang)之上再橫鋪石(shi)(shi)橋(qiao)(qiao)(qiao)板。這(zhe)在古代石(shi)(shi)橋(qiao)(qiao)(qiao)中(zhong)并不(bu)多見。大橋(qiao)(qiao)(qiao)加(jia)上小橋(qiao)(qiao)(qiao)總長700多米,氣勢雄偉壯觀(guan)。橋(qiao)(qiao)(qiao)南(nan)還建(jian)造(zao)鎮橋(qiao)(qiao)(qiao)塔2座(zuo),分(fen)列(lie)左右,塔七級六(liu)角(jiao)。
龍江橋(qiao)歷(li)史久(jiu)遠,由于洪水、颶(ju)風、海潮的頻(pin)頻(pin)襲擊(ji),自明(ming)嘉靖二十三年(1544年)至(zhi)民國的400年間,累代(dai)修葺(qi),可考的有10數次,平均每(mei)二、三十年大(da)修一(yi)次。當地紳衿、耆民為表其(qi)功績,立碑(bei)紀念,石(shi)(shi)碑(bei)現仍立在橋(qiao)頭(tou)。共(gong)和國成(cheng)立后,政(zheng)府多次撥款維修,先后把第六(liu)、七、二十六(liu)孔(kong)的木橋(qiao)面改修為石(shi)(shi)橋(qiao)面,石(shi)(shi)梁斷折亦隨毀(hui)隨修。1961年5月,列為福建(jian)省第一(yi)批重(zhong)點文物保護單位。